Operation not allowed on sorted list - System::Classes::TStringList::InsertObject

Trying to add an Amazon S3 bucket in the Login window. As soon as I select "Amazon S3" from the dropdown, I get three "Operation not allowed on sorted list" errors with the following Stack traces (in order).

WinSCP 6.0

Error message:
Operation not allowed on sorted list

Stack trace 1:
(001FA940) System::Classes::TStringList::InsertObject
(001FA940) System::Classes::TStringList::InsertObject
(001FA91E) System::Classes::TStringList::Insert
(00E6F5D2) TLoginDialog::UpdateControls
(00E6FB94) TLoginDialog::DataChange
(003F4F51) Vcl::Controls::TWinControl::WndProc
(003F0048) Vcl::Controls::TControl::Perform
(003F50B7) Vcl::Controls::_17076
(003F4F51) Vcl::Controls::TWinControl::WndProc
(003F4598) Vcl::Controls::TWinControl::MainWndProc
(00213A0C) System::Classes::_18201
(00040489) USER32.dll
(00037445) USER32.dll
(00037045) USER32.dll
(0003AC0D) USER32.dll
(00073FBB) ntdll.dll.KiUserCallbackDispatcher
(00034E6A) USER32.dll.SendMessageW
(00072335) COMCTL32.DLL
(0007286B) COMCTL32.DLL
(00040489) USER32.dll
(00037445) USER32.dll
(00036B22) USER32.dll
(00034CC6) USER32.dll.CallWindowProcW
(003F5062) Vcl::Controls::TWinControl::DefaultHandler
(003F4F51) Vcl::Controls::TWinControl::WndProc
(003F0048) Vcl::Controls::TControl::Perform
(003F0060) Vcl::Controls::TControl::Perform
(003EDE91) Vcl::Controls::TControl::SetTextBuf
(00E73D21) TLoginDialog::TransferProtocolComboChange
(0035B5CC) Vcl::Stdctrls::TCustomCombo::Change
(0035B797) Vcl::Stdctrls::TCustomCombo::Select
(003F040D) Vcl::Controls::TControl::WndProc
(003F4F51) Vcl::Controls::TWinControl::WndProc
(0035B427) Vcl::Stdctrls::TCustomCombo::WndProc
(003F0048) Vcl::Controls::TControl::Perform
(003F50B7) Vcl::Controls::_17076
(003F4F51) Vcl::Controls::TWinControl::WndProc
(003F4598) Vcl::Controls::TWinControl::MainWndProc
(00213A0C) System::Classes::_18201
(00040489) USER32.dll
(00037445) USER32.dll
(00037045) USER32.dll
(0003AC0D) USER32.dll
(00073FBB) ntdll.dll.KiUserCallbackDispatcher
(00034E6A) USER32.dll.SendMessageW
(000472B5) COMCTL32.DLL
(00041D59) COMCTL32.DLL
(00040489) USER32.dll
(00037445) USER32.dll
(00036B22) USER32.dll
(00034CC6) USER32.dll.CallWindowProcW
(003F5062) Vcl::Controls::TWinControl::DefaultHandler
(003F4F51) Vcl::Controls::TWinControl::WndProc
(0035B427) Vcl::Stdctrls::TCustomCombo::WndProc
(003F4598) Vcl::Controls::TWinControl::MainWndProc
(00213A0C) System::Classes::_18201
(00040489) USER32.dll
(00037445) USER32.dll
(00037045) USER32.dll
(0003AC0D) USER32.dll
(00073FBB) ntdll.dll.KiUserCallbackDispatcher
(00034E6A) USER32.dll.SendMessageW
(000F1AAA) COMCTL32.DLL
(000ADD19) COMCTL32.DLL
(00040489) USER32.dll
(00037445) USER32.dll
(000351B5) USER32.dll
(00034F7B) USER32.dll.DispatchMessageW

Stack trace 2:
(001FA940) System::Classes::TStringList::InsertObject
(001FA940) System::Classes::TStringList::InsertObject
(001FA91E) System::Classes::TStringList::Insert
(00E6F5D2) TLoginDialog::UpdateControls
(00E6FB94) TLoginDialog::DataChange
(0035B5CC) Vcl::Stdctrls::TCustomCombo::Change
(0035B797) Vcl::Stdctrls::TCustomCombo::Select
(003F040D) Vcl::Controls::TControl::WndProc
(003F4F51) Vcl::Controls::TWinControl::WndProc
(0035B427) Vcl::Stdctrls::TCustomCombo::WndProc
(003F0048) Vcl::Controls::TControl::Perform
(003F50B7) Vcl::Controls::_17076
(003F4F51) Vcl::Controls::TWinControl::WndProc
(003F4598) Vcl::Controls::TWinControl::MainWndProc
(00213A0C) System::Classes::_18201
(00040489) USER32.dll
(00037445) USER32.dll
(00037045) USER32.dll
(0003AC0D) USER32.dll
(00073FBB) ntdll.dll.KiUserCallbackDispatcher
(00034E6A) USER32.dll.SendMessageW
(000472B5) COMCTL32.DLL
(00041D59) COMCTL32.DLL
(00040489) USER32.dll
(00037445) USER32.dll
(00036B22) USER32.dll
(00034CC6) USER32.dll.CallWindowProcW
(003F5062) Vcl::Controls::TWinControl::DefaultHandler
(003F4F51) Vcl::Controls::TWinControl::WndProc
(0035B427) Vcl::Stdctrls::TCustomCombo::WndProc
(003F4598) Vcl::Controls::TWinControl::MainWndProc
(00213A0C) System::Classes::_18201
(00040489) USER32.dll
(00037445) USER32.dll
(00037045) USER32.dll
(0003AC0D) USER32.dll
(00073FBB) ntdll.dll.KiUserCallbackDispatcher
(00034E6A) USER32.dll.SendMessageW
(000F1AAA) COMCTL32.DLL
(000ADD19) COMCTL32.DLL
(00040489) USER32.dll
(00037445) USER32.dll
(000351B5) USER32.dll
(00034F7B) USER32.dll.DispatchMessageW

Stack trace 3:
(001FA940) System::Classes::TStringList::InsertObject
(001FA940) System::Classes::TStringList::InsertObject
(001FA91E) System::Classes::TStringList::Insert
(00E6F5D2) TLoginDialog::UpdateControls
(00E7157B) TLoginDialog::ActionListUpdate
(002618C4) System::Actions::TContainedActionList::UpdateAction
(0034548E) Vcl::Actnlist::TCustomAction::Update
(003B40DE) Vcl::Forms::_16777
(003B40DE) Vcl::Forms::_16777
(003B415C) Vcl::Forms::TCustomForm::UpdateActions

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.

@khigby: 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.

@khigby: I have added this bug to the tracker:
Issue 2166 – Failure when selecting S3 protocol in Login dialog with non-existing .aws/credentials file

I'm sending you an email with a development version of WinSCP to the address you have used to register on this forum.