<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 5.17.6

Error message:
メモリのアクセス違反

スタック トレース:
(00007724) TCustomScpExplorerForm::QueueChanged
(00F87E4E) C5296_0
(00F89EB6) ____ExceptionHandler
(00F86C70) __ExceptionHandler
(0006246E) ntdll.dll
(0000F12E) ntdll.dll.KiUserExceptionDispatcher
(00007172) TCustomScpExplorerForm::SetQueue
(0004D036) TScpCommanderForm::~TScpCommanderForm
(00102882) Execute
(00002658) wWinMain
(00F85E61) __wstartup
(00038810) ntdll.dll
(000387E0) ntdll.dll

(00F894B7) C5296_0
(00F87E4E) C5296_0
(00F89EB6) ____ExceptionHandler
(00F86C70) __ExceptionHandler
(0006246E) ntdll.dll
(0000F12E) ntdll.dll.KiUserExceptionDispatcher
(00F89819) C5296_0
(00F88D07) C5296_0
(00F89CFD) ____ExceptionHandler
(00F86C70) __ExceptionHandler
(0006246E) ntdll.dll
(00F87DDE) ___doGlobalUnwind
(00F89FCA) ____ExceptionHandler
(00F86C70) __ExceptionHandler
(0006246E) ntdll.dll
(0000F12E) ntdll.dll.KiUserExceptionDispatcher
(00007172) TCustomScpExplorerForm::SetQueue
(0004D036) TScpCommanderForm::~TScpCommanderForm
(00102882) Execute
(00002658) wWinMain
(00F85E61) __wstartup
(00038810) ntdll.dll
(000387E0) ntdll.dll

The problem happens rarely. I cannot reproduce it.