Invalid access to memory - Dragdrop::TDragDrop::ExecuteOperation

<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 5.17.5

Error message:
Invalid access to memory.

Stack trace:
(000599CE) OLE32.DLL
(00087E3F) ntdll.dll
(000732D1) ntdll.dll.KiUserExceptionDispatcher
(000886C4) OLE32.DLL
(000854F6) OLE32.DLL
(000892E5) OLE32.DLL
(00087832) OLE32.DLL
(00088BF3) OLE32.DLL.DoDragDrop
(0047C863) Dragdrop::TDragDrop::ExecuteOperation
(004434C3) Customdirview::TCustomizableDragDropFilesEx::Execute
(00C3CA82) TUnixDirView::DDDragDetect
(00443C52) Customdirview::TCustomDirView::CNNotify
(00275301) Vcl::Controls::TControl::WndProc
(00279E45) Vcl::Controls::TWinControl::WndProc
(002BD11F) Vcl::Comctrls::TCustomListView::WndProc
(00279FAB) Vcl::Controls::_17076
(00279E45) Vcl::Controls::TWinControl::WndProc
(0027948C) Vcl::Controls::TWinControl::MainWndProc
(003A4AA8) System::Classes::_18201
(00043449) USER32.dll
(00023F87) USER32.dll
(00023B25) USER32.dll
(0002D16D) USER32.dll
(0007328B) ntdll.dll.KiUserCallbackDispatcher
(000233FE) USER32.dll.SendMessageW
(00059AA1) COMCTL32.DLL
(0019DBB3) COMCTL32.DLL
(0019E4B3) COMCTL32.DLL
(0008E16F) COMCTL32.DLL
(00053D62) COMCTL32.DLL
(00043449) USER32.dll
(00023F87) USER32.dll
(000234DA) USER32.dll.CallWindowProcW
(00279F56) Vcl::Controls::TWinControl::DefaultHandler
(0044569E) Customdirview::TCustomDirView::WMLButtonDown
(00279E45) Vcl::Controls::TWinControl::WndProc
(002BD11F) Vcl::Comctrls::TCustomListView::WndProc
(003A4AA8) System::Classes::_18201
(00043449) USER32.dll
(00023F87) USER32.dll
(000234DA) USER32.dll.CallWindowProcW
(00075CA7) COMCTL32.DLL
(00075D46) COMCTL32.DLL
(00075A5C) COMCTL32.DLL
(00043449) USER32.dll
(00023F87) USER32.dll
(000234DA) USER32.dll.CallWindowProcW
(0047BD83) Dragdrop::TDragDrop::WndMethod
(003A4AA8) System::Classes::_18201
(00043449) USER32.dll
(00023F87) USER32.dll
(000230D9) USER32.dll
(00022EBB) USER32.dll.DispatchMessageW

(000599CE) OLE32.DLL
(00087E3F) ntdll.dll
(000732D1) ntdll.dll.KiUserExceptionDispatcher
(000886C4) OLE32.DLL
(000854F6) OLE32.DLL
(000892E5) OLE32.DLL
(00087832) OLE32.DLL
(00088BF3) OLE32.DLL.DoDragDrop
(0047C863) Dragdrop::TDragDrop::ExecuteOperation
(004434C3) Customdirview::TCustomizableDragDropFilesEx::Execute
(00C3CA82) TUnixDirView::DDDragDetect
(00443C52) Customdirview::TCustomDirView::CNNotify
(00275301) Vcl::Controls::TControl::WndProc
(00279E45) Vcl::Controls::TWinControl::WndProc
(002BD11F) Vcl::Comctrls::TCustomListView::WndProc
(00279FAB) Vcl::Controls::_17076
(00279E45) Vcl::Controls::TWinControl::WndProc
(0027948C) Vcl::Controls::TWinControl::MainWndProc
(003A4AA8) System::Classes::_18201
(00043449) USER32.dll
(00023F87) USER32.dll
(00023B25) USER32.dll
(0002D16D) USER32.dll
(0007328B) ntdll.dll.KiUserCallbackDispatcher
(000233FE) USER32.dll.SendMessageW
(00059AA1) COMCTL32.DLL
(0019DBB3) COMCTL32.DLL
(0019E4B3) COMCTL32.DLL
(0008E16F) COMCTL32.DLL
(00053D62) COMCTL32.DLL
(00043449) USER32.dll
(00023F87) USER32.dll
(000234DA) USER32.dll.CallWindowProcW
(00279F56) Vcl::Controls::TWinControl::DefaultHandler
(0044569E) Customdirview::TCustomDirView::WMLButtonDown
(00279E45) Vcl::Controls::TWinControl::WndProc
(002BD11F) Vcl::Comctrls::TCustomListView::WndProc
(003A4AA8) System::Classes::_18201
(00043449) USER32.dll
(00023F87) USER32.dll
(000234DA) USER32.dll.CallWindowProcW
(00075CA7) COMCTL32.DLL
(00075D46) COMCTL32.DLL
(00075A5C) COMCTL32.DLL
(00043449) USER32.dll
(00023F87) USER32.dll
(000234DA) USER32.dll.CallWindowProcW
(0047BD83) Dragdrop::TDragDrop::WndMethod
(003A4AA8) System::Classes::_18201
(00043449) USER32.dll
(00023F87) USER32.dll
(000230D9) USER32.dll
(00022EBB) USER32.dll.DispatchMessageW

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.

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 5.18

Error message:
Invalid access to memory.

Stack trace:
(000599CE) OLE32.DLL
(00087E3F) ntdll.dll
(000732D1) ntdll.dll.KiUserExceptionDispatcher
(000886C4) OLE32.DLL
(000854F6) OLE32.DLL
(000892E5) OLE32.DLL
(00087832) OLE32.DLL
(00088BF3) OLE32.DLL.DoDragDrop
(005B80C9) Dragdrop::TDragDrop::ExecuteOperation
(005603A3) Customdirview::TCustomizableDragDropFilesEx::Execute
(0056955B) Customdirview::TCustomDirView::DDDragDetect
(00581EDB) Dirview::TDirView::DDDragDetect
(00560E5E) Customdirview::TCustomDirView::CNNotify
(001D90C9) Vcl::Controls::TControl::WndProc
(001DED67) Vcl::Controls::TWinControl::WndProc
(002BE757) Vcl::Comctrls::TCustomListView::WndProc
(001D8BCA) Vcl::Controls::TControl::Perform
(001DEF54) Vcl::Controls::_17099
(001DFB5F) Vcl::Controls::TWinControl::WMNotify
(001D90C9) Vcl::Controls::TControl::WndProc
(001DED67) Vcl::Controls::TWinControl::WndProc
(001DE2B8) Vcl::Controls::TWinControl::MainWndProc
(004D2584) System::Classes::_18201
(000434B9) USER32.dll
(00023FF7) USER32.dll
(00023B95) USER32.dll
(0002D1DD) USER32.dll
(0007328B) ntdll.dll.KiUserCallbackDispatcher
(0002346E) USER32.dll.SendMessageW
(00059AA1) COMCTL32.DLL
(0019DBB3) COMCTL32.DLL
(0019E4B3) COMCTL32.DLL
(0008E16F) COMCTL32.DLL
(00053D62) COMCTL32.DLL
(000434B9) USER32.dll
(00023FF7) USER32.dll
(0002354A) USER32.dll.CallWindowProcW
(001DEEDA) Vcl::Controls::TWinControl::DefaultHandler
(001D986B) Vcl::Controls::TControl::WMLButtonDown
(002C0220) Vcl::Comctrls::TCustomListView::WMLButtonDown
(0053F032) Nortonlikelistview::TCustomNortonLikeListView::WMLButtonDown
(00564980) Customdirview::TCustomDirView::WMLButtonDown
(001D90C9) Vcl::Controls::TControl::WndProc
(001DED67) Vcl::Controls::TWinControl::WndProc
(002BE757) Vcl::Comctrls::TCustomListView::WndProc
(001DE2B8) Vcl::Controls::TWinControl::MainWndProc
(004D2584) System::Classes::_18201
(000434B9) USER32.dll
(00023FF7) USER32.dll
(0002354A) USER32.dll.CallWindowProcW
(00075CA7) COMCTL32.DLL
(00075D46) COMCTL32.DLL
(00075A5C) COMCTL32.DLL
(000434B9) USER32.dll
(00023FF7) USER32.dll
(0002354A) USER32.dll.CallWindowProcW
(005B6FE7) Dragdrop::TDragDrop::WndMethod
(004D2584) System::Classes::_18201
(000434B9) USER32.dll
(00023FF7) USER32.dll
(00023149) USER32.dll
(00022F2B) USER32.dll.DispatchMessageW
(0025C7EF) Vcl::Forms::TApplication::ProcessMessage
(0025C83F) Vcl::Forms::TApplication::HandleMessage
(0025CBF3) Vcl::Forms::TApplication::Run
(0012D1CC) Execute
(0000318D) wWinMain
(011522E5) __wstartup
(00066C22) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00066BEF) ntdll.dll.RtlGetAppContainerNamedObjectPath

(000599CE) OLE32.DLL
(00087E3F) ntdll.dll
(000732D1) ntdll.dll.KiUserExceptionDispatcher
(000886C4) OLE32.DLL
(000854F6) OLE32.DLL
(000892E5) OLE32.DLL
(00087832) OLE32.DLL
(00088BF3) OLE32.DLL.DoDragDrop
(005B80C9) Dragdrop::TDragDrop::ExecuteOperation
(005603A3) Customdirview::TCustomizableDragDropFilesEx::Execute
(0056955B) Customdirview::TCustomDirView::DDDragDetect
(00581EDB) Dirview::TDirView::DDDragDetect
(00560E5E) Customdirview::TCustomDirView::CNNotify
(001D90C9) Vcl::Controls::TControl::WndProc
(001DED67) Vcl::Controls::TWinControl::WndProc
(002BE757) Vcl::Comctrls::TCustomListView::WndProc
(001D8BCA) Vcl::Controls::TControl::Perform
(001DEF54) Vcl::Controls::_17099
(001DFB5F) Vcl::Controls::TWinControl::WMNotify
(001D90C9) Vcl::Controls::TControl::WndProc
(001DED67) Vcl::Controls::TWinControl::WndProc
(001DE2B8) Vcl::Controls::TWinControl::MainWndProc
(004D2584) System::Classes::_18201
(000434B9) USER32.dll
(00023FF7) USER32.dll
(00023B95) USER32.dll
(0002D1DD) USER32.dll
(0007328B) ntdll.dll.KiUserCallbackDispatcher
(0002346E) USER32.dll.SendMessageW
(00059AA1) COMCTL32.DLL
(0019DBB3) COMCTL32.DLL
(0019E4B3) COMCTL32.DLL
(0008E16F) COMCTL32.DLL
(00053D62) COMCTL32.DLL
(000434B9) USER32.dll
(00023FF7) USER32.dll
(0002354A) USER32.dll.CallWindowProcW
(001DEEDA) Vcl::Controls::TWinControl::DefaultHandler
(001D986B) Vcl::Controls::TControl::WMLButtonDown
(002C0220) Vcl::Comctrls::TCustomListView::WMLButtonDown
(0053F032) Nortonlikelistview::TCustomNortonLikeListView::WMLButtonDown
(00564980) Customdirview::TCustomDirView::WMLButtonDown
(001D90C9) Vcl::Controls::TControl::WndProc
(001DED67) Vcl::Controls::TWinControl::WndProc
(002BE757) Vcl::Comctrls::TCustomListView::WndProc
(001DE2B8) Vcl::Controls::TWinControl::MainWndProc
(004D2584) System::Classes::_18201
(000434B9) USER32.dll
(00023FF7) USER32.dll
(0002354A) USER32.dll.CallWindowProcW
(00075CA7) COMCTL32.DLL
(00075D46) COMCTL32.DLL
(00075A5C) COMCTL32.DLL
(000434B9) USER32.dll
(00023FF7) USER32.dll
(0002354A) USER32.dll.CallWindowProcW
(005B6FE7) Dragdrop::TDragDrop::WndMethod
(004D2584) System::Classes::_18201
(000434B9) USER32.dll
(00023FF7) USER32.dll
(00023149) USER32.dll
(00022F2B) USER32.dll.DispatchMessageW
(0025C7EF) Vcl::Forms::TApplication::ProcessMessage
(0025C83F) Vcl::Forms::TApplication::HandleMessage
(0025CBF3) Vcl::Forms::TApplication::Run
(0012D1CC) Execute
(0000318D) wWinMain
(011522E5) __wstartup
(00066C22) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00066BEF) 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 5.19.6

Error message:
Invalid access to memory.

Stack trace:
(001239E2) combase.dll
(0008788F) ntdll.dll
(00073EC1) ntdll.dll.KiUserExceptionDispatcher
(00069510) combase.dll.InternalGetWindowPropInterface2
(0001D411) OLE32.DLL.ReadFmtUserTypeStg
(000AF51F) OLE32.DLL
(000AF7DF) OLE32.DLL
(0007746D) OLE32.DLL
(000791D4) OLE32.DLL
(0007983C) OLE32.DLL.DoDragDrop
(0049F24B) Dragdrop::TDragDrop::ExecuteOperation
(004664FF) Customdirview::TCustomizableDragDropFilesEx::Execute
(00C6EF9E) TUnixDirView::DDDragDetect
(00466C9A) Customdirview::TCustomDirView::CNNotify
(0027B89D) Vcl::Controls::TControl::WndProc
(002803E1) Vcl::Controls::TWinControl::WndProc
(002C36BB) Vcl::Comctrls::TCustomListView::WndProc
(00280547) Vcl::Controls::_17076
(002803E1) Vcl::Controls::TWinControl::WndProc
(0027FA28) Vcl::Controls::TWinControl::MainWndProc
(003C7B64) System::Classes::_18201
(00040099) USER32.dll
(00037055) USER32.dll
(00036C55) USER32.dll
(0003A81D) USER32.dll
(00073E7B) ntdll.dll.KiUserCallbackDispatcher
(00034A7A) USER32.dll.SendMessageW
(00068881) COMCTL32.DLL
(0019EF20) COMCTL32.DLL
(000A3C35) COMCTL32.DLL
(000648A2) COMCTL32.DLL
(00040099) USER32.dll
(00037055) USER32.dll
(00036732) USER32.dll
(000348D6) USER32.dll.CallWindowProcW
(002804F2) Vcl::Controls::TWinControl::DefaultHandler
(004686E6) Customdirview::TCustomDirView::WMLButtonDown
(002803E1) Vcl::Controls::TWinControl::WndProc
(002C36BB) Vcl::Comctrls::TCustomListView::WndProc
(003C7B64) System::Classes::_18201
(00040099) USER32.dll
(00037055) USER32.dll
(00036732) USER32.dll
(000348D6) USER32.dll.CallWindowProcW
(00079E57) COMCTL32.DLL
(00079EF6) COMCTL32.DLL
(00079CAC) COMCTL32.DLL
(00040099) USER32.dll
(00037055) USER32.dll
(00036732) USER32.dll
(000348D6) USER32.dll.CallWindowProcW
(0049E76B) Dragdrop::TDragDrop::WndMethod
(003C7B64) System::Classes::_18201
(00040099) USER32.dll
(00037055) USER32.dll
(00034DC5) USER32.dll
(00034B8B) USER32.dll.DispatchMessageW

(001239E2) combase.dll
(0008788F) ntdll.dll
(00073EC1) ntdll.dll.KiUserExceptionDispatcher
(00069510) combase.dll.InternalGetWindowPropInterface2
(0001D411) OLE32.DLL.ReadFmtUserTypeStg
(000AF51F) OLE32.DLL
(000AF7DF) OLE32.DLL
(0007746D) OLE32.DLL
(000791D4) OLE32.DLL
(0007983C) OLE32.DLL.DoDragDrop
(0049F24B) Dragdrop::TDragDrop::ExecuteOperation
(004664FF) Customdirview::TCustomizableDragDropFilesEx::Execute
(00C6EF9E) TUnixDirView::DDDragDetect
(00466C9A) Customdirview::TCustomDirView::CNNotify
(0027B89D) Vcl::Controls::TControl::WndProc
(002803E1) Vcl::Controls::TWinControl::WndProc
(002C36BB) Vcl::Comctrls::TCustomListView::WndProc
(00280547) Vcl::Controls::_17076
(002803E1) Vcl::Controls::TWinControl::WndProc
(0027FA28) Vcl::Controls::TWinControl::MainWndProc
(003C7B64) System::Classes::_18201
(00040099) USER32.dll
(00037055) USER32.dll
(00036C55) USER32.dll
(0003A81D)%

The problem happens rarely. I cannot reproduce it.