<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 5.17.9

Error message:
无效的内存访问。

Stack trace:
(000AC24A) TTerminalManager::DisconnectActiveTerminal
(0008776F) ntdll.dll
(00073E91) ntdll.dll.KiUserExceptionDispatcher
(000195DC) TCustomScpExplorerForm::DisconnectSession
(003E9378) System::Actions::TContainedActionList::ExecuteAction
(001C7F61) Vcl::Actnlist::TCustomAction::Execute
(003A5954) System::Classes::_18201
(0003DEB9) USER32.dll
(00034E75) USER32.dll
(00032BE5) USER32.dll
(000329AB) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.