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 5.17.10

Error message:
メモリのアクセス違反

スタック トレース:
(0041A028) System::UStrAsg
(000878AF) ntdll.dll
(00073EE1) ntdll.dll.KiUserExceptionDispatcher
(00085D34) TFrameAnimation::CalculateNextFrameTick
(00085CE4) TFrameAnimation::Animate
(003A5978) System::Classes::_18201
(0003DEB9) USER32.dll
(00034E75) USER32.dll
(00032BE5) USER32.dll
(000329AB) 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.