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.
Start the WinSCP
It gives this error.
WinSCP 5.15.3
Error message:
Invalid access to memory.
Stack trace:
(00045E60) UXTHEME.DLL
(00087C8F) ntdll.dll
(00073131) ntdll.dll.KiUserExceptionDispatcher
(00279BF8) Vcl::Controls::TWinControl::WMPaint
(0027EF2D) Vcl::Controls::TCustomControl::WMPaint
(0027919D) Vcl::Controls::TWinControl::WndProc
(002787E4) Vcl::Controls::TWinControl::MainWndProc
(003A3E00) System::Classes::_18201
(000438E9) USER32.dll
(00025137) USER32.dll
(00024CD5) USER32.dll
(0002D6BD) USER32.dll
(000730EB) ntdll.dll.KiUserCallbackDispatcher
(0002406B) 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.