Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>
Hello,
problem always happend when the target server is unaviable for longer time.

WinSCP 5.17.5

Error message:
Canvas does not allow drawing

Stack trace:
(00273DBE) Vcl::Controls::TControl::GetDeviceContext
(00271F47) Vcl::Controls::TControlCanvas::CreateHandle
(0021CA65) Vcl::Graphics::TCanvas::RequiredState
(001DCF03) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001DD134) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00274F3C) Vcl::Controls::TControl::Perform
(00272D95) Vcl::Controls::TControl::SetTextBuf
(002737FF) Vcl::Controls::TControl::SetName
(00E05DCB) TMessageForm::Create
(00E07D71) CreateMoreMessageDialog
(000EEA4F) CreateMessageDialogEx
(000EF2C0) CreateMoreMessageDialogEx
(000EF43A) MoreMessageDialog
(000F0F88) ExceptionMessageDialog
(000F1209) FatalExceptionMessageDialog
(000BD61D) ShowExtendedExceptionEx
(00021CF0) TCustomScpExplorerForm::ShowExtendedException
(000AD6A1) TTerminalManager::TerminalShowExtendedException
(00D8C694) TTerminal::ShowExtendedException
(000AC052) TTerminalManager::ReconnectActiveTerminal
(000BD733) ShowExtendedExceptionEx
(00021CF0) TCustomScpExplorerForm::ShowExtendedException
(000AD6A1) TTerminalManager::TerminalShowExtendedException
(00D8C694) TTerminal::ShowExtendedException
(0023DD8E) Vcl::Forms::TApplication::HandleException
(003A4AA8) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167BF) USER32.dll
(00016885) USER32.dll.DispatchMessageW

(0021CA83) Vcl::Graphics::TCanvas::RequiredState
(004B4F48) Tbx::TTBXItemViewer::CalcSize
(0049EE04) Tb2item::TTBView::

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.17.3

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00273AF6) Vcl::Controls::TControl::GetDeviceContext
(00271C7F) Vcl::Controls::TControlCanvas::CreateHandle
(0021C79D) Vcl::Graphics::TCanvas::RequiredState
(001DCC3B) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001DCE6C) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00274C74) Vcl::Controls::TControl::Perform
(00272ACD) Vcl::Controls::TControl::SetTextBuf
(00273537) Vcl::Controls::TControl::SetName
(00E0582F) TMessageForm::Create
(00E077D5) CreateMoreMessageDialog
(000EE787) CreateMessageDialogEx
(000EEFF8) CreateMoreMessageDialogEx
(000EF172) MoreMessageDialog
(000F0CC0) ExceptionMessageDialog
(000BD550) ShowExtendedExceptionEx
(00021CEC) TCustomScpExplorerForm::ShowExtendedException
(000AD65D) TTerminalManager::TerminalShowExtendedException
(00D8C23C) TTerminal::ShowExtendedException
(0023DAC6) Vcl::Forms::TApplication::HandleException
(00102522) Execute
(00002658) wWinMain
(00F856F1) C5164_0
(00064E15) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00064DE2) ntdll.dll.RtlGetAppContainerNamedObjectPath

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.13.4

Error message:
The parameter is incorrect.


Stack trace:
(0025594E) Vcl::Controls::TControl::GetDeviceContext
(00253AD7) Vcl::Controls::TControlCanvas::CreateHandle
(001FE5F5) Vcl::Graphics::TCanvas::RequiredState
(001BEA93) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001BECC4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00256ACC) Vcl::Controls::TControl::Perform
(00254925) Vcl::Controls::TControl::SetTextBuf
(0025538F) Vcl::Controls::TControl::SetName
(0082A537) TMessageForm::Create
(0082C4DD) CreateMoreMessageDialog
(000D1203) CreateMessageDialogEx
(000D1A70) CreateMoreMessageDialogEx
(000D1C42) MoreMessageDialog
(000D3748) ExceptionMessageDialog
(000D3A09) FatalExceptionMessageDialog
(000A4CD0) ShowExtendedExceptionEx
(0001D6F4) TCustomScpExplorerForm::ShowExtendedException
(00097969) TTerminalManager::TerminalShowExtendedException
(007B94BC) TTerminal::ShowExtendedException
(0009646A) TTerminalManager::ReconnectActiveTerminal
(000A4DE5) ShowExtendedExceptionEx
(0001D6F4) TCustomScpExplorerForm::ShowExtendedException
(00097969) TTerminalManager::TerminalShowExtendedException
(007B94BC) TTerminal::ShowExtendedException
(0021F91E) Vcl::Forms::TApplication::HandleException
(00380D20) System::Classes::_18201
(0003AF19) USER32.dll
(000373E5) USER32.dll
(00036C99) USER32.dll
(00036A7B) USER32.dll.DispatchMessageW

(001FE897) Vcl::Graphics::_16680
(001FE8CF) Vcl::Graphics::_16681
(00203ACB) Vcl::Graphics::TBitmap::CopyImage
(00205661) Vcl::Graphics::TBitmap::SetPixelFormat
(004A83BA) Pngimagelist::_16436
(004A8740) Pngimagelist::TPngImageList::PngToIcon
(004A7254) Pngimagelist::TPngImageList::AddPng
(00026252) TCustomScpExplorerForm::AddFixedSessionImage
(00005E9A) TCustomScpExplorerForm::TerminalChanged
(00005DA8) TCustomScpExplorerForm::SetTerminal
(000967CB) TTerminalManager::DoSetActiveTerminal
(00096756) TTerminalManager::SetActiveTerminal
(00095C9F) TTerminalManager::FreeActiveTerminal
(000A4DE5) ShowExtendedExceptionEx
(0001D6F4) TCustomScpExplorerForm::ShowExtendedException
(00097969) TTerminalManager::TerminalShowExtendedException
(007B94BC) TTerminal::ShowExtendedException
(0021F91E) Vcl::Forms::TApplication::HandleException
(00380D20) System::Classes::_18201
(0003AF19) USER32.dll
(000373E5) USER32.dll
(00036C99) USER32.dll
(00036A7B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.13.2

Error message:
De parameter is onjuist.


Stack trace:
(00254E5A) Vcl::Controls::TControl::GetDeviceContext
(00252FE3) Vcl::Controls::TControlCanvas::CreateHandle
(001FDB01) Vcl::Graphics::TCanvas::RequiredState
(001BDF9F) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001BE1D0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00255FD8) Vcl::Controls::TControl::Perform
(00253E31) Vcl::Controls::TControl::SetTextBuf
(0025489B) Vcl::Controls::TControl::SetName
(00829027) TMessageForm::Create
(0082AFCD) CreateMoreMessageDialog
(000D070F) CreateMessageDialogEx
(000D0F7C) CreateMoreMessageDialogEx
(000D114E) MoreMessageDialog
(000D2C54) ExceptionMessageDialog
(000D2F15) FatalExceptionMessageDialog
(000A4340) ShowExtendedExceptionEx
(0001D6B4) TCustomScpExplorerForm::ShowExtendedException
(0009703D) TTerminalManager::TerminalShowExtendedException
(007B8178) TTerminal::ShowExtendedException
(00095B3E) TTerminalManager::ReconnectActiveTerminal
(000A4455) ShowExtendedExceptionEx
(0001D6B4) TCustomScpExplorerForm::ShowExtendedException
(0009703D) TTerminalManager::TerminalShowExtendedException
(007B8178) TTerminal::ShowExtendedException
(0021EE2A) Vcl::Forms::TApplication::HandleException
(0038022C) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167BF) USER32.dll
(00016885) USER32.dll.DispatchMessageW

(001FDDA3) Vcl::Graphics::_16680
(001FDDDB) Vcl::Graphics::_16681
(00202FD7) Vcl::Graphics::TBitmap::CopyImage
(0

The problem happens rarely. I cannot reproduce it.

I had connected to a remote SFTP host and was transferring a file. The connection was lost (server-side issues) and I was waiting for the connection to come back up. I left the application running overnight; I am unsure how long after the connection was lost that this error occurred.

WinSCP 5.13.3

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00254F9E) Vcl::Controls::TControl::GetDeviceContext
(00253127) Vcl::Controls::TControlCanvas::CreateHandle
(001FDC45) Vcl::Graphics::TCanvas::RequiredState
(001BE0E3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001BE314) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0025611C) Vcl::Controls::TControl::Perform
(00253F75) Vcl::Controls::TControl::SetTextBuf
(002549DF) Vcl::Controls::TControl::SetName
(008293BB) TMessageForm::Create
(0082B361) CreateMoreMessageDialog
(000D0853) CreateMessageDialogEx
(000D10C0) CreateMoreMessageDialogEx
(000D1292) MoreMessageDialog
(000D2D98) ExceptionMessageDialog
(000A44EF) ShowExtendedExceptionEx
(0001D6F4) TCustomScpExplorerForm::ShowExtendedException
(00097121) TTerminalManager::TerminalShowExtendedException
(007B8102) TTerminal::HandleExtendedException
(007BB81E) TTerminal::CommandError
(007BB5B1) TTerminal::CommandError
(007D10AE) TTerminal::CopyToLocal
(0000E861) TCustomScpExplorerForm::ExecuteFileOperation
(0000F530) TCustomScpExplorerForm::ExecuteFileOperation
(0001E6C7) TCustomScpExplorerForm::RemoteFileControlFileOperation
(0001EA8D) TCustomScpExplorerForm::RemoteFileControlDDEnd
(00420706) Customdirview::TCustomDirView::DDDragDetect
(0067A35E) TUnixDirView::DDDragDetect
(0041CB90) Customdirview::TCustomDirView::CNNotify
(002564E1) Vcl::Controls::TControl::WndProc
(0025B025) Vcl::Controls::TWinControl::WndProc
(0029EF53) Vcl::Comctrls::TCustomListView::WndProc
(0025B18B) Vcl::Controls::_17076
(0025B025) Vcl::Controls::TWinControl::WndProc
(0025A66C) Vcl::Controls::TWinControl::MainWndProc
(00380370) System::Classes::_18201
(0003AE69) USER32.dll
(00037335) USER32.dll
(00036ED5) USER32.dll
(00039627) USER32.dll
(0006B66B) ntdll.dll.KiUserCallbackDispatcher
(0001AC52) USER32.dll.SendMessageW
(0003947D) COMCTL32.DLL
(0019212D) COMCTL32.DLL
(0005BDAA) COMCTL32.DLL
(0002D8C2) COMCTL32.DLL
(0003AE69) USER32.dll
(00037335) USER32.dll
(00016AF8) USER32.dll.CallWindowProcW
(0025B136) Vcl::Controls::TWinControl::DefaultHandler
(0041E3C2) Customdirview::TCustomDirView::WMLButtonDown
(0025B025) Vcl::Controls::TWinControl::WndProc
(0029EF53) Vcl::Comctrls::TCustomListView::WndProc
(00380370) System::Classes::_18201
(0003AE69) USER32.dll
(00037335) USER32.dll
(00016AF8) USER32.dll.CallWindowProcW
(00049AD7) COMCTL32.DLL
(00049B76) COMCTL32.DLL
(00049930) COMCTL32.DLL
(0003AE69) USER32.dll
(00037335) USER32.dll
(00016AF8) USER32.dll.CallWindowProcW
(00443213) Dragdrop::TDragDrop::WndMethod
(00380370) System::Classes::_18201
(0003AE69) USER32.dll
(00037335) USER32.dll
(00036BE9) USER32.dll
(000369CB) USER32.dll.DispatchMessageW

(008BD0C5) C5104_0
(008BE69F) _ReThrowException
(007B8295) TTerminal::HandleExtendedException
(007BB81E) TTerminal::CommandError
(007BB5B1) TTerminal::CommandError
(007D10AE) TTerminal::CopyToLocal
(0000E861) TCustomScpExplorerForm::ExecuteFileOperation
(0000F530) TCustomScpExplorerForm::ExecuteFileOperation
(0001E6C7) TCustomScpExplorerForm::RemoteFileControlFileOperation
(0001EA8D) TCustomScpExplorerForm::RemoteFileControlDDEnd
(00420706) Customdirview::TCustomDirView::DDDragDetect
(0067A35E) TUnixDirView::DDDragDetect
(0041CB90) Customdirview::TCustomDirView::CNNotify
(002564E1) Vcl::Controls::TControl::WndProc
(0025B025) Vcl::Controls::TWinControl::WndProc
(0029EF53) Vcl::Comctrls::TCustomListView::WndProc
(0025B18B) Vcl::Controls::_17076
(0025B025) Vcl::Controls::TWinControl::WndProc
(0025A66C) Vcl::Controls::TWinControl::MainWndProc
(00380370) System::Classes::_18201
(0003AE69) USER32.dll
(00037335) USER32.dll
(00036ED5) USER32.dll
(00039627) USER32.dll
(0006B66B) ntdll.dll.KiUserCallbackDispatcher
(0001AC52) USER32.dll.SendMessageW
(0003947D) COMCTL32.DLL
(0019212D) COMCTL32.DLL
(0005BDAA) COMCTL32.DLL
(0002D8C2) COMCTL32.DLL
(0003AE69) USER32.dll
(00037335) USER32.dll
(00016AF8) USER32.dll.CallWindowProcW
(0025B136) Vcl::Controls::TWinControl::DefaultHandler
(0041E3C2) Customdirview::TCustomDirView::WMLButtonDown
(0025B025) Vcl::Controls::TWinControl::WndProc
(0029EF53) Vcl::Comctrls::TCustomListView::WndProc
(00380370) System::Classes::_18201
(0003AE69) USER32.dll
(00037335) USER32.dll
(00016AF8) USER32.dll.CallWindowProcW
(00049AD7) COMCTL32.DLL
(00049B76) COMCTL32.DLL
(00049930) COMCTL32.DLL
(0003AE69) USER32.dll
(00037335) USER32.dll
(00016AF8) USER32.dll.CallWindowProcW
(00443213) Dragdrop::TDragDrop::WndMethod
(00380370) System::Classes::_18201
(0003AE69) USER32.dll
(00037335) USER32.dll
(00036BE9) USER32.dll
(000369CB) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

копирование на ftp запускаешь, минимизируешь окно и в конце копирования такая проблема возникает.

WinSCP 5.11.3

Error message:
Копирование файлов на сервер не удалось.

Control 'Message' has no parent window

Трассировка стека:
(00251C42) Vcl::Controls::TControl::GetDeviceContext
(0024FDCB) Vcl::Controls::TControlCanvas::CreateHandle
(001FA8E9) Vcl::Graphics::TCanvas::RequiredState
(001BAD87) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001BAFB8) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00252DC0) Vcl::Controls::TControl::Perform
(00250C19) Vcl::Controls::TControl::SetTextBuf
(00251683) Vcl::Controls::TControl::SetName
(0080CC0B) TMessageForm::Create
(0080EB41) CreateMoreMessageDialog
(000CDDAF) CreateMessageDialogEx
(000CE61C) CreateMoreMessageDialogEx
(000CE7EE) MoreMessageDialog
(0001D25A) TCustomScpExplorerForm::MoreMessageDialog
(00094817) TTerminalManager::TerminalQueryUser
(0079953E) TTerminal::QueryUser
(0079998E) TTerminal::QueryUserException
(0079ACF6) TTerminal::DoQueryReopen
(0079AE2A) TTerminal::QueryReopen
(00791D55) TRobustOperationLoop::TryReopen
(006BADDE) TFTPFileSystem::SourceRobust
(006BAB86) TFTPFileSystem::CopyToRemote
(007B0319) TTerminal::CopyToRemote
(0000E312) TCustomScpExplorerForm::ExecuteFileOperation
(0001FAEC) TCustomScpExplorerForm::RemoteFileControlDragDropFileOperation
(0001FC78) TCustomScpExplorerForm::RemoteFileControlDDFileOperation
%

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.11.1

Error message:
Parâmetro incorreto.


Rastreamento de pilha:
(00251B1A) Vcl::Controls::TControl::GetDeviceContext
(0024FCA3) Vcl::Controls::TControlCanvas::CreateHandle
(001FA7C1) Vcl::Graphics::TCanvas::RequiredState
(001BAC5F) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001BAE90) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00252C98) Vcl::Controls::TControl::Perform
(00250AF1) Vcl::Controls::TControl::SetTextBuf
(0025155B) Vcl::Controls::TControl::SetName
(0080C263) TMessageForm::Create
(0080E199) CreateMoreMessageDialog
(000CDCBB) CreateMessageDialogEx
(000CE528) CreateMoreMessageDialogEx
(000CE6FA) MoreMessageDialog
(000D0200) ExceptionMessageDialog
(000D04C1) FatalExceptionMessageDialog
(000A1E51) ShowExtendedExceptionEx
(0001D368) TCustomScpExplorerForm::ShowExtendedException
(00094C4D) TTerminalManager::TerminalShowExtendedException
(007996F4) TTerminal::ShowExtendedException
(00093752) TTerminalManager::ReconnectActiveTerminal
(000A1F66) ShowExtendedExceptionEx
(0001D368) TCustomScpExplorerForm::ShowExtendedException
(00094C4D) TTerminalManager::TerminalShowExtendedException
(007996F4) TTerminal::ShowExtendedException
(0021BAEA) Vcl::Forms::TApplication::HandleException
(0037BB94) System::Classes::_18201
(0001D0B9) USER32.dll
(00027844) USER32.dll
(0002A140) USER32.dll
(000180D7) USER32.dll
(00017C1B) USER32.dll.DispatchMessageW

(001FAA63) Vcl::Graphics::_16680
(001FAA9B) Vcl::Graphics::_16681
(001FFC97) Vcl::Graphics::TBitmap::CopyImage
(0020182D) Vcl::Graphics::TBitmap::SetPixelFormat
(004A268E) Pngimagelist::_16434
(004A2A14) Pngimagelist::TPngImageList::PngToIcon
(004A15C4) Pngimagelist::TPngImageList::AddPng
(000257B6) TCustomScpExplorerForm::AddFixedSessionImage
(00005B76) TCustomScpExplorerForm::TerminalChanged
(00005A84) TCustomScpExplorerForm::SetTerminal
(00093AB3) TTerminalManager::DoSetActiveTerminal
(00093A3E) TTerminalManager::SetActiveTerminal
(00093017) TTerminalManager::FreeActiveTerminal
(000A1F66) ShowExtendedExceptionEx
(0001D368) TCustomScpExplorerForm::ShowExtendedException
(00094C4D) TTerminalManager::TerminalShowExtendedException
(007996F4) TTerminal::ShowExtendedException
(0021BAEA) Vcl::Forms::TApplication::HandleException
(0037BB94) System::Classes::_18201
(0001D0B9) USER32.dll
(00027844) USER32.dll
(0002A140) USER32.dll
(000180D7) USER32.dll
(00017C1B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.9.4

Error message:
Control 'MainMessage' has no parent window

스택 추적:
(002491E2) Vcl::Controls::TControl::GetDeviceContext
(00247353) Vcl::Controls::TControlCanvas::CreateHandle
(001F1E71) Vcl::Graphics::TCanvas::RequiredState
(001B230F) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001B2540) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0024A360) Vcl::Controls::TControl::Perform
(002481A1) Vcl::Controls::TControl::SetTextBuf
(00248C0B) Vcl::Controls::TControl::SetName
(007DDEDE) TMessageForm::Create
(007E0029) CreateMoreMessageDialog
(000C59CB) CreateMessageDialogEx
(000C6238) CreateMoreMessageDialogEx
(000C640A) MoreMessageDialog
(000C7F10) ExceptionMessageDialog
(00099CA2) ShowExtendedExceptionEx
(0008CF3C) TTerminalManager::TerminalShowExtendedException
(00772E0C) TTerminal::ShowExtendedException
(0021319A) Vcl::Forms::TApplication::HandleException
(0037322C) System::Classes::_18201
(0001B4B4) USER32.dll
(0001B5B2) USER32.dll
(0001BBE4) USER32.dll
(0001BC3B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.9.2

Error message:
Paramètre incorrect.


Stack trace:
(00248BA2)
(00246D13)
(001F1831)
(001B1CCF)
(001B1F00)
(00249D20)
(00247B61)
(002485CB)
(007DB38E)
(007DD4D9)
(000C5503)
(000C5D70)
(000C5F42)
(000C7A38)
(000C7CF9)
(00099682)
(0001CB64)
(0008CC4D)
(007706B4)
(0008B60A)
(000996FF)
(0001CB64)
(0008CC4D)
(007706B4)
(00212B5A)
(00372BEC)
(0002C2B1) USER32.dll
(0000D885) USER32.dll
(0000D1DF) USER32.dll
(0000CF9B) USER32.dll.DispatchMessageW

(001F1AD3)
(001F1B0B)
(001F6D07)
(001F889D)
(0048A56A)
(0048A8F0)
(00489560)
(00024E12)
(00005BB2)
(00005AC0)
(0008B96B)
(0008B8F6)
(0008AF2F)
(000996FF)
(0001CB64)
(0008CC4D)
(007706B4)
(00212B5A)
(00372BEC)
(0002C2B1) USER32.dll
(0000D885) USER32.dll
(0000D1DF) USER32.dll
(0000CF9B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.9.2

Error message:
Control 'MainMessage' has no parent window

Трассировка стека:
(00248BA2) Vcl::Controls::TControl::GetDeviceContext
(00246D13) Vcl::Controls::TControlCanvas::CreateHandle
(001F1831) Vcl::Graphics::TCanvas::RequiredState
(001B1CCF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001B1F00) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00249D20) Vcl::Controls::TControl::Perform
(00247B61) Vcl::Controls::TControl::SetTextBuf
(002485CB) Vcl::Controls::TControl::SetName
(007DB38E) TMessageForm::Create
(007DD4D9) CreateMoreMessageDialog
(000C5503) CreateMessageDialogEx
(000C5D70) CreateMoreMessageDialogEx
(000C5F42) MoreMessageDialog
(000C7A38) ExceptionMessageDialog
(000998E6) ShowExtendedExceptionEx
(0008CC58) TTerminalManager::TerminalShowExtendedException
(007706B4) TTerminal::ShowExtendedException
(00212B5A) Vcl::Forms::TApplication::HandleException
(00372BEC) System::Classes::_18201
(000374F1) USER32.dll
(00015C3B) USER32.dll
(0001553C) USER32.dll
(000152FB) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.9.2

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00248BA2) Vcl::Controls::TControl::GetDeviceContext
(00246D13) Vcl::Controls::TControlCanvas::CreateHandle
(001F1831) Vcl::Graphics::TCanvas::RequiredState
(001B1CCF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001B1F00) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00249D20) Vcl::Controls::TControl::Perform
(00247B61) Vcl::Controls::TControl::SetTextBuf
(002485CB) Vcl::Controls::TControl::SetName
(007DB38E) TMessageForm::Create
(007DD4D9) CreateMoreMessageDialog
(000C5503) CreateMessageDialogEx
(000C5D70) CreateMoreMessageDialogEx
(000C5F42) MoreMessageDialog
(000C7A38) ExceptionMessageDialog
(000998E6) ShowExtendedExceptionEx
(0008CC58) TTerminalManager::TerminalShowExtendedException
(007706B4) TTerminal::ShowExtendedException
(00212B5A) Vcl::Forms::TApplication::HandleException
(00372BEC) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167BF) USER32.dll
(00016885) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

Not sure what happened, just came back to my computer after a while, to this error message (asking me to send report, here it is )

WinSCP 5.9.2

Error message:
The parameter is incorrect.


Stack trace:
(00248BA2)
(00246D13)
(001F1831)
(001B1CCF)
(001B1F00)
(00249D20)
(00247B61)
(002485CB)
(007DB38E)
(007DD4D9)
(000C5503)
(000C5D70)
(000C5F42)
(000C7A38)
(000C7CF9)
(00099682)
(0001CB64)
(0008CC4D)
(007706B4)
(0008B60A)
(000996FF)
(0001CB64)
(0008CC4D)
(007706B4)
(00212B5A)
(00372BEC)
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167BF) USER32.dll
(00016885) USER32.dll.DispatchMessageW

(001F1AD3)
(001F1B0B)
(001F6D07)
(001F889D)
(0048A56A)
(0048A8F0)
(00489560)
(00024E12)
(00005BB2)
(00005AC0)
(0008B96B)
(0008B8F6)
(0008AF2F)
(000996FF)
(0001CB64)
(0008CC4D)
(007706B4)
(00212B5A)
(00372BEC)
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167BF) USER32.dll
(00016885) USER32.dll.DispatchMessageW :) :) :) :)

The problem happens rarely. I cannot reproduce it.

connect to host using winscp. Disconnect network forcing winscp to try to reconnect. allow to "fester" until it confuses itself and this error happens. (likely a race condition between windows.

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216582#
#002146F3#
#001BFB05#
#0017FFA3#
#001801D4#
#00217700#
#00215541#
#00215FAB#
#00768ED5#
#0076AFD5#
#0009F2DA#
#0009FA45#
#000A1160#
#0008378A#
#00082ED8#
#000A9A85#
#00002462#
#007DEA01#
#00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.9.2

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00248BA2) Vcl::Controls::TControl::GetDeviceContext
(00246D13) Vcl::Controls::TControlCanvas::CreateHandle
(001F1831) Vcl::Graphics::TCanvas::RequiredState
(001B1CCF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001B1F00) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00249D20) Vcl::Controls::TControl::Perform
(00247B61) Vcl::Controls::TControl::SetTextBuf
(002485CB) Vcl::Controls::TControl::SetName
(007DB38E) TMessageForm::Create
(007DD4D9) CreateMoreMessageDialog
(000C5503) CreateMessageDialogEx
(000C5D70) CreateMoreMessageDialogEx
(000C5F42) MoreMessageDialog
(000C7A38) ExceptionMessageDialog
(000998E6) ShowExtendedExceptionEx
(0001CB64) TCustomScpExplorerForm::ShowExtendedException
(0008CC4D) TTerminalManager::TerminalShowExtendedException
(007706B4) TTerminal::ShowExtendedException
(00212B5A) Vcl::Forms::TApplication::HandleException
(007D2C62) TLoginDialog::Dispatch
(0024EC29) Vcl::Controls::TWinControl::WndProc
(002090D8) Vcl::Forms::TCustomForm::WndProc
(008093C5) Vclcommon::C2754_0
(00249D20) Vcl::Controls::TControl::Perform
(0024E019) Vcl::Controls::TWinControl::UpdateShowing
(0024E128) Vcl::Controls::TWinControl::UpdateControlState
(00250CCE) Vcl::Controls::TWinControl::CMVisibleChanged
(0024EC29) Vcl::Controls::TWinControl::WndProc
(002090D8) Vcl::Forms::TCustomForm::WndProc
(008094EC) Vclcommon::C2754_0
(00249D20) Vc

The problem happens rarely. I cannot reproduce it.

Running unattended in the background to a host that wasn't always able to connect. Had it running for at least 30 hours, then this error occurred by surprise.

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216582)
(002146F3)
(001BFB05)
(0017FFA3)
(001801D4)
(00217700)
(00215541)
(00215FAB)
(00768ED5)
(0076AFD5)
(0009F2DA)
(0009FA45)
(000A1160)
(0008378A)
(00082ED8)
(000A9A85)
(00002462)
(007DEA01)
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(00062AB1) ntdll.dll
(00062A81) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.9.2

Error message:
The parameter is incorrect.


Stack trace:
(00248BA2) Vcl::Controls::TControl::GetDeviceContext
(00246D13) Vcl::Controls::TControlCanvas::CreateHandle
(001F1831) Vcl::Graphics::TCanvas::RequiredState
(001B1CCF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001B1F00) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00249D20) Vcl::Controls::TControl::Perform
(00247B61) Vcl::Controls::TControl::SetTextBuf
(002485CB) Vcl::Controls::TControl::SetName
(007DB38E) TMessageForm::Create
(007DD4D9) CreateMoreMessageDialog
(000C5503) CreateMessageDialogEx
(000C5D70) CreateMoreMessageDialogEx
(000C5F42) MoreMessageDialog
(000C7A38) ExceptionMessageDialog
(000C7CF9) FatalExceptionMessageDialog
(00099682) ShowExtendedExceptionEx
(0001CB64) TCustomScpExplorerForm::ShowExtendedException
(0008CC4D) TTerminalManager::TerminalShowExtendedException
(007706B4) TTerminal::ShowExtendedException
(0008B60A) TTerminalManager::ReconnectActiveTerminal
(000996FF) ShowExtendedExceptionEx
(0001CB64) TCustomScpExplorerForm::ShowExtendedException
(0008CC4D) TTerminalManager::TerminalShowExtendedException
(007706B4) TTerminal::ShowExtendedException
(00212B5A) Vcl::Forms::TApplication::HandleException
(00372BEC) System::Classes::_18201
(00007E6F) USER32.DLL.CallNextHookEx
(000080CC) USER32.DLL
(00009625) USER32.DLL
(0000967B) USER32.DLL.DispatchMessageW

(001F1AD3) Vcl::Graphics::_16680
(001F1B0B) Vcl::Graphics::_16681
(001F6D07) Vcl::Graphics::TBitmap::Co

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.3

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00215E6E) Vcl::Controls::TControl::GetDeviceContext
(00213FDF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF3F1) Vcl::Graphics::TCanvas::RequiredState
(0017F88F) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FAC0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00216FEC) Vcl::Controls::TControl::Perform
(00214E2D) Vcl::Controls::TControl::SetTextBuf
(00215897) Vcl::Controls::TControl::SetName
(007663C9) TMessageForm::Create
(007684C9) CreateMoreMessageDialog
(0009F19E) CreateMessageDialogEx
(0009F909) MoreMessageDialog
(000A1024) ExceptionMessageDialog
(000836BE) ShowExtendedExceptionEx
(0001AA78) TCustomScpExplorerForm::ShowExtendedException
(00077B11) TTerminalManager::TerminalShowExtendedException
(0070D350) TTerminal::ShowExtendedException
(000A9371) Execute
(00002462) wWinMain
(007DFDF9) C4667_0
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(000382E0) ntdll.dll
(000382B0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>
I left my computer for the night then came back and it had this message. Looks like it was trying to reconnect to a host when this happened.

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(0001AB28) TCustomScpExplorerForm::ShowExtendedException
(00077BDD) TTerminalManager::TerminalShowExtendedException
(0070F0E8) TTerminal::ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(00029240) ntdll.dll
(00029210) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
[002866CE] Vcl::Controls::TControl::GetDeviceContext
[0028483F] Vcl::Controls::TControlCanvas::CreateHandle
[0022FC51] Vcl::Graphics::TCanvas::RequiredState
[001F00EF] Vcl::Stdctrls::TCustomLabel::AdjustBounds
[001F0320] Vcl::Stdctrls::TCustomLabel::CMTextChanged
[0028784C] Vcl::Controls::TControl::Perform
[0028568D] Vcl::Controls::TControl::SetTextBuf
[002860F7] Vcl::Controls::TControl::SetName
[007D4F29] TMessageForm::Create
[007D7029] CreateMoreMessageDialog
[0010F9FE] CreateMessageDialogEx
[00110169] MoreMessageDialog
[00111884] ExceptionMessageDialog
[000F4252] ShowExtendedExceptionEx
[000F39A0] ShowExtendedException
[00119BD1] Execute
[00073456] wWinMain
[0084E735] __wstartup
[76EC9900] ntdll.dll
[76EC98D0] ntdll.dll

The problem happens rarely. I cannot reproduce it.

Left WinSCP ruuning over a weekend with approx. 4-5 open connections.

Logged in Monday morning and found this stack trace on the desktop.

btw. apparently the Win7 host that WinSCP was running on got disconnected from the network during the weekend.

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216582) Vcl::Controls::TControl::GetDeviceContext
(002146F3) Vcl::Controls::TControlCanvas::CreateHandle
(001BFB05) Vcl::Graphics::TCanvas::RequiredState
(0017FFA3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001801D4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217700) Vcl::Controls::TControl::Perform
(00215541) Vcl::Controls::TControl::SetTextBuf
(00215FAB) Vcl::Controls::TControl::SetName
(00768ED5) TMessageForm::Create
(0076AFD5) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00077BE8) TTerminalManager::TerminalShowExtendedException
(0070FC38) TTerminal::ShowExtendedException
(0034059C) System::Classes::_18201
(000152F7) USER32.dll
(00015D35) USER32.dll
(000167CE) USER32.dll
(00016895) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Трассировка стека:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Трассировка стека:
(00216582) Vcl::Controls::TControl::GetDeviceContext
(002146F3) Vcl::Controls::TControlCanvas::CreateHandle
(001BFB05) Vcl::Graphics::TCanvas::RequiredState
(0017FFA3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001801D4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217700) Vcl::Controls::TControl::Perform
(00215541) Vcl::Controls::TControl::SetTextBuf
(00215FAB) Vcl::Controls::TControl::SetName
(00768ED5) TMessageForm::Create
(0076AFD5) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9A85) Execute
(00002462) wWinMain
(007DEA01) C4667_0
(00059D1D) ntdll.dll
(00059CE5) ntdll.dll

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.

Left it running over a four day weekend, unlocked my computer and was presented with the dialog that brought me here when I clicked 'Report'. I have no idea what would specifically trigger the issue. I do recall being connected to four different SFTP sessions where two of those servers frequently disconnect me - if one of those tabs is selected, WinSCP will generally try to reconnect. Perhaps there is something funky when a desktop is locked and a server disconnects.

<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216582) Vcl::Controls::TControl::GetDeviceContext
(002146F3) Vcl::Controls::TControlCanvas::CreateHandle
(001BFB05) Vcl::Graphics::TCanvas::RequiredState
(0017FFA3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001801D4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217700) Vcl::Controls::TControl::Perform
(00215541) Vcl::Controls::TControl::SetTextBuf
(00215FAB) Vcl::Controls::TControl::SetName
(00768ED5) TMessageForm::Create
(0076AFD5) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(0001AB28) TCustomScpExplorerForm::ShowExtendedException
(00077BDD) TTerminalManager::TerminalShowExtendedException
(0070FC38) TTerminal::ShowExtendedException
(000A9A85) Execute
(00002462) wWinMain
(007DEA01) C4667_0
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216582) Vcl::Controls::TControl::GetDeviceContext
(002146F3) Vcl::Controls::TControlCanvas::CreateHandle
(001BFB05) Vcl::Graphics::TCanvas::RequiredState
(0017FFA3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001801D4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217700) Vcl::Controls::TControl::Perform
(00215541) Vcl::Controls::TControl::SetTextBuf
(00215FAB) Vcl::Controls::TControl::SetName
(00768ED5) TMessageForm::Create
(0076AFD5) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9A85) Execute
(00002462) wWinMain
(007DEA01) C4667_0
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
Seems to be related to a WinSCP window being left open, though this is the first time I've seen this Error, so it definitely happens rarely.
The window was connected to a Google cloud Linux instance which was unintentionally left open for ~48hrs.
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

I have let Winscp stay connected via ssh with the Linux server in a vpn.
After a time the vpn got disconnected and connection to server too.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216582#
#002146F3#
#001BFB05#
#0017FFA3#
#001801D4#
#00217700#
#00215541#
#00215FAB#
#00768ED5#
#0076AFD5#
#0009F2DA#
#0009FA45#
#000A1160#
#0008378A#
#00082ED8#
#000A9A85#
#00002462#
#007DEA01#
#00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

stack trace:
(00216582) Vcl::Controls::TControl::GetDeviceContext
(002146F3) Vcl::Controls::TControlCanvas::CreateHandle
(001BFB05) Vcl::Graphics::TCanvas::RequiredState
(0017FFA3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001801D4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217700) Vcl::Controls::TControl::Perform
(00215541) Vcl::Controls::TControl::SetTextBuf
(00215FAB) Vcl::Controls::TControl::SetName
(00768ED5) TMessageForm::Create
(0076AFD5) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(0001AB28) TCustomScpExplorerForm::ShowExtendedException
(00077BDD) TTerminalManager::TerminalShowExtendedException
(0070FC38) TTerminal::ShowExtendedException
(000A9A85) Execute
(00002462) wWinMain
(007DEA01) C4667_0
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

スタック トレース:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

I had WinSCP open for several days but the client was no longer connected. Eventually this error message appears while the session was inactive.

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216582) Vcl::Controls::TControl::GetDeviceContext
(002146F3) Vcl::Controls::TControlCanvas::CreateHandle
(001BFB05) Vcl::Graphics::TCanvas::RequiredState
(0017FFA3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001801D4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217700) Vcl::Controls::TControl::Perform
(00215541) Vcl::Controls::TControl::SetTextBuf
(00215FAB) Vcl::Controls::TControl::SetName
(00768ED5) TMessageForm::Create
(0076AFD5) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9A85) Execute
(00002462) wWinMain
(007DEA01) C4667_0
(00038A00) ntdll.dll
(000389D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

left on for a few days maybe? idk what else happened.

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216582) Vcl::Controls::TControl::GetDeviceContext
(002146F3) Vcl::Controls::TControlCanvas::CreateHandle
(001BFB05) Vcl::Graphics::TCanvas::RequiredState
(0017FFA3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001801D4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217700) Vcl::Controls::TControl::Perform
(00215541) Vcl::Controls::TControl::SetTextBuf
(00215FAB) Vcl::Controls::TControl::SetName
(00768ED5) TMessageForm::Create
(0076AFD5) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9A85) Execute
(00002462) wWinMain
(007DEA01) C4667_0
(00038F70) ntdll.dll
(00038F40) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.5

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216272) Vcl::Controls::TControl::GetDeviceContext
(002143E3) Vcl::Controls::TControlCanvas::CreateHandle
(001BF7F5) Vcl::Graphics::TCanvas::RequiredState
(0017FC93) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEC4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(002173F0) Vcl::Controls::TControl::Perform
(00215231) Vcl::Controls::TControl::SetTextBuf
(00215C9B) Vcl::Controls::TControl::SetName
(00767689) TMessageForm::Create
(00769789) CreateMoreMessageDialog
(0009F2C2) CreateMessageDialogEx
(0009FA2D) MoreMessageDialog
(000A1148) ExceptionMessageDialog
(00083772) ShowExtendedExceptionEx
(00082EC0) ShowExtendedException
(000A9775) Execute
(00002462) wWinMain
(007E1B41) C4667_0
(00038900) ntdll.dll
(000388D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.7

Error message:
Control 'MainMessage' has no parent window

スタック トレース:
(00216582) Vcl::Controls::TControl::GetDeviceContext
(002146F3) Vcl::Controls::TControlCanvas::CreateHandle
(001BFB05) Vcl::Graphics::TCanvas::RequiredState
(0017FFA3) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(001801D4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217700) Vcl::Controls::TControl::Perform
(00215541) Vcl::Controls::TControl::SetTextBuf
(00215FAB) Vcl::Controls::TControl::SetName
(00768ED5) TMessageForm::Create
(0076AFD5) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9A85) Execute
(00002462) wWinMain
(007DEA01) C4667_0
(00062B51) ntdll.dll
(00062B21) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(0021628E)
(002143FF)
(001BF811)
(0017FCAF)
(0017FEE0)
(0021740C)
(0021524D)
(00215CB7)
(00768359)
(0076A459)
(0009F2DA)
(0009FA45)
(000A1160)
(0008378A)
(0001AB28)
(00077BDD)
(0070F0E8)
(000A9791)
(00002462)
(007E2811)
(00038A00) ntdll.dll
(000389D0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

I was just sitting and watching browser, doing literally nothing with the app minimized. Then this pop up suddenly flashing asking me to send this. The app wasn't closed for several days, maybe even week(s) (I don't cared about it and just maximized it when needed), the connections were certainly lost during several hybernates.
This is really not a trouble for me, but well, it asked nicely to send this and is really a nice app ;) It is the first time I've encountered it.

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(0001AB28) TCustomScpExplorerForm::ShowExtendedException
(00077BDD) TTerminalManager::TerminalShowExtendedException
(0070F0E8) TTerminal::ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(0005AD97) ntdll.dll
(0005AD67) ntdll.dll

The problem happens rarely. I cannot reproduce it.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

I've encountered this same error. WinSCP 5.7.6. I had left WinSCP open overnight, I think connected to a server via SFTP. When returning to my PC, I saw the error.

Stack trace:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(00038880) ntdll.dll
(00038850) ntdll.dll

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Трассировка стека:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(0004F48C) ntdll.dll
(0004F458) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7

Error message:
Control 'MainMessage' has no parent window

Stack trace:
[005266CE] Vcl::Controls::TControl::GetDeviceContext
[0052483F] Vcl::Controls::TControlCanvas::CreateHandle
[004CFC51] Vcl::Graphics::TCanvas::RequiredState
[004900EF] Vcl::Stdctrls::TCustomLabel::AdjustBounds
[00490320] Vcl::Stdctrls::TCustomLabel::CMTextChanged
[0052784C] Vcl::Controls::TControl::Perform
[0052568D] Vcl::Controls::TControl::SetTextBuf
[005260F7] Vcl::Controls::TControl::SetName
[00A74F29] TMessageForm::Create
[00A77029] CreateMoreMessageDialog
[003AF9FE] CreateMessageDialogEx
[003B0169] MoreMessageDialog
[003B1884] ExceptionMessageDialog
[00394252] ShowExtendedExceptionEx
[0032B9C8] TCustomScpExplorerForm::ShowExtendedException
[00388715] TTerminalManager::TerminalShowExtendedException
[00A1C2C4] TTerminal::ShowExtendedException
[003B9BD1] Execute
[00313456] wWinMain
[00AEE735] __wstartup
[779A9880] ntdll.dll
[779A9850] ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.5

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216272) Vcl::Controls::TControl::GetDeviceContext
(002143E3) Vcl::Controls::TControlCanvas::CreateHandle
(001BF7F5) Vcl::Graphics::TCanvas::RequiredState
(0017FC93) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEC4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(002173F0) Vcl::Controls::TControl::Perform
(00215231) Vcl::Controls::TControl::SetTextBuf
(00215C9B) Vcl::Controls::TControl::SetName
(00767689) TMessageForm::Create
(00769789) CreateMoreMessageDialog
(0009F2C2) CreateMessageDialogEx
(0009FA2D) MoreMessageDialog
(000A1148) ExceptionMessageDialog
(00083772) ShowExtendedExceptionEx
(00082EC0) ShowExtendedException
(000A9775) Execute
(00002462) wWinMain
(007E1B41) C4667_0
(00059D5D) ntdll.dll
(00059D25) ntdll.dll

The problem happens rarely. I cannot reproduce it.

happens sporadically. usually when trying to refresh the list of files

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.5

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216272) Vcl::Controls::TControl::GetDeviceContext
(002143E3) Vcl::Controls::TControlCanvas::CreateHandle
(001BF7F5) Vcl::Graphics::TCanvas::RequiredState
(0017FC93) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEC4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(002173F0) Vcl::Controls::TControl::Perform
(00215231) Vcl::Controls::TControl::SetTextBuf
(00215C9B) Vcl::Controls::TControl::SetName
(00767689) TMessageForm::Create
(00769789) CreateMoreMessageDialog
(0009F2C2) CreateMessageDialogEx
(0009FA2D) MoreMessageDialog
(000A1148) ExceptionMessageDialog
(00083772) ShowExtendedExceptionEx
(00082EC0) ShowExtendedException
(000A9775) Execute
(00002462) wWinMain
(007E1B41) C4667_0
(00038880) ntdll.dll
(00038850) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.6

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(0021628E) Vcl::Controls::TControl::GetDeviceContext
(002143FF) Vcl::Controls::TControlCanvas::CreateHandle
(001BF811) Vcl::Graphics::TCanvas::RequiredState
(0017FCAF) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEE0) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(0021740C) Vcl::Controls::TControl::Perform
(0021524D) Vcl::Controls::TControl::SetTextBuf
(00215CB7) Vcl::Controls::TControl::SetName
(00768359) TMessageForm::Create
(0076A459) CreateMoreMessageDialog
(0009F2DA) CreateMessageDialogEx
(0009FA45) MoreMessageDialog
(000A1160) ExceptionMessageDialog
(0008378A) ShowExtendedExceptionEx
(00082ED8) ShowExtendedException
(000A9791) Execute
(00002462) wWinMain
(007E2811) C4667_0
(000387F0) ntdll.dll
(000387C0) ntdll.dll

The problem happens rarely. I cannot reproduce it.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.5

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00216272) Vcl::Controls::TControl::GetDeviceContext
(002143E3) Vcl::Controls::TControlCanvas::CreateHandle
(001BF7F5) Vcl::Graphics::TCanvas::RequiredState
(0017FC93) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FEC4) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(002173F0) Vcl::Controls::TControl::Perform
(00215231) Vcl::Controls::TControl::SetTextBuf
(00215C9B) Vcl::Controls::TControl::SetName
(00767689) TMessageForm::Create
(00769789) CreateMoreMessageDialog
(0009F2C2) CreateMessageDialogEx
(0009FA2D) MoreMessageDialog
(000A1148) ExceptionMessageDialog
(00083772) ShowExtendedExceptionEx
(00082EC0) ShowExtendedException
(000A9775) Execute
(00002462) wWinMain
(007E1B41) C4667_0
(00038880) ntdll.dll
(00038850) ntdll.dll

The problem happens rarely. I cannot reproduce it.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.4

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00215FE2) Vcl::Controls::TControl::GetDeviceContext
(00214153) Vcl::Controls::TControlCanvas::CreateHandle
(001BF565) Vcl::Graphics::TCanvas::RequiredState
(0017FA03) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FC34) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217160) Vcl::Controls::TControl::Perform
(00214FA1) Vcl::Controls::TControl::SetTextBuf
(00215A0B) Vcl::Controls::TControl::SetName
(007670D5) TMessageForm::Create
(007691D5) CreateMoreMessageDialog
(0009F2AE) CreateMessageDialogEx
(0009FA19) MoreMessageDialog
(000A1134) ExceptionMessageDialog
(0008375E) ShowExtendedExceptionEx
(00082EAC) ShowExtendedException
(000A94E5) Execute
(00002462) wWinMain
(007E15A1) C4667_0
(000382B0) ntdll.dll
(00038280) ntdll.dll

Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.4

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00215FE2) Vcl::Controls::TControl::GetDeviceContext
(00214153) Vcl::Controls::TControlCanvas::CreateHandle
(001BF565) Vcl::Graphics::TCanvas::RequiredState
(0017FA03) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017FC34) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00217160) Vcl::Controls::TControl::Perform
(00214FA1) Vcl::Controls::TControl::SetTextBuf
(00215A0B) Vcl::Controls::TControl::SetName
(007670D5) TMessageForm::Create
(007691D5) CreateMoreMessageDialog
(0009F2AE) CreateMessageDialogEx
(0009FA19) MoreMessageDialog
(000A1134) ExceptionMessageDialog
(0008375E) ShowExtendedExceptionEx
(00082EAC) ShowExtendedException
(000A94E5) Execute
(00002462) wWinMain
(007E15A1) C4667_0
(000382E0) ntdll.dll
(000382B0) ntdll.dll

Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.2

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00215942) Vcl::Controls::TControl::GetDeviceContext
(00213AB3) Vcl::Controls::TControlCanvas::CreateHandle
(001BEEC5) Vcl::Graphics::TCanvas::RequiredState
(0017F363) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017F594) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00216AC0) Vcl::Controls::TControl::Perform
(00214901) Vcl::Controls::TControl::SetTextBuf
(0021536B) Vcl::Controls::TControl::SetName
(0076559D) TMessageForm::Create
(0076769D) CreateMoreMessageDialog
(0009EC72) CreateMessageDialogEx
(0009F3DD) MoreMessageDialog
(000A0AF8) ExceptionMessageDialog
(000832E2) ShowExtendedExceptionEx
(00082A30) ShowExtendedException
(000A8E45) Execute
(00002462) wWinMain
(007DEFC5) C4667_0
(000382B0) ntdll.dll
(00038280) ntdll.dll

Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.2

Error message:
Control 'MainMessage' has no parent window

Stack trace:
(00215942) Vcl::Controls::TControl::GetDeviceContext
(00213AB3) Vcl::Controls::TControlCanvas::CreateHandle
(001BEEC5) Vcl::Graphics::TCanvas::RequiredState
(0017F363) Vcl::Stdctrls::TCustomLabel::AdjustBounds
(0017F594) Vcl::Stdctrls::TCustomLabel::CMTextChanged
(00216AC0) Vcl::Controls::TControl::Perform
(00214901) Vcl::Controls::TControl::SetTextBuf
(0021536B) Vcl::Controls::TControl::SetName
(0076559D) TMessageForm::Create
(0076769D) CreateMoreMessageDialog
(0009EC72) CreateMessageDialogEx
(0009F3DD) MoreMessageDialog
(000A0AF8) ExceptionMessageDialog
(000832E2) ShowExtendedExceptionEx
(00082A30) ShowExtendedException
(000A8E45) Execute
(00002462) wWinMain
(007DEFC5) C4667_0
(000382B0) ntdll.dll
(00038280) ntdll.dll

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.6.3

Error message:
Control 'MainMessage' has no parent window

Stack trace:
[01265A12] Vcl::Controls::TControl::GetDeviceContext
[01263B83] Vcl::Controls::TControlCanvas::CreateHandle
[0120EF95] Vcl::Graphics::TCanvas::RequiredState
[011CF433] Vcl::Stdctrls::TCustomLabel::AdjustBounds
[011CF664] Vcl::Stdctrls::TCustomLabel::CMTextChanged
[01266B90] Vcl::Controls::TControl::Perform
[012649D1] Vcl::Controls::TControl::SetTextBuf
[0126543B] Vcl::Controls::TControl::SetName
[017ABDC6] TMessageForm::Create
[017ADF85] CreateMoreMessageDialog
[010EEF3A] CreateMessageDialogEx
[010EF6B5] MoreMessageDialog
[010F0DD0] ExceptionMessageDialog
[010D3792] ShowExtendedExceptionEx
[010D2EE0] ShowExtendedException
[010F8F15] Execute
[01053456] wWinMain
[01824CD9] C4595_0
[777A9F70] ntdll.dll
[777A9F40] ntdll.dll