<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 5.13.3

Error message:
Accès mémoire invalide.

Trace de la pile :
(00409053) Pastools::GetMonitorPixelsPerInch
(0007DA8F) ntdll.dll
(0006B6B1) ntdll.dll.KiUserExceptionDispatcher
(004533A7) Tb2dock::TTBCustomDockableWindow::WMNCPaint
(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

The problem happens rarely. I cannot reproduce it.