<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:
Ошибка доступа к памяти.

Трассировка стека:
(00267FA0) __tpdsc__ Vcl::Controls::TMouseActivateEvent
(00F87E4E) C5296_0
(00F89EB6) ____ExceptionHandler
(00F86C70) __ExceptionHandler
(00087E3F) ntdll.dll
(000732D1) ntdll.dll.KiUserExceptionDispatcher
(00CBCFA7) TTerminalQueue::GetIsEmpty
(00008B77) TCustomScpExplorerForm::AddQueueItem
(000153E2) TCustomScpExplorerForm::ExecutedFileChanged
(00071A3D) TEditorManager::CheckFileChange
(0006FA2A) TEditorManager::Check
(00018C78) TCustomScpExplorerForm::Idle
(00049A73) TNonVisualDataModule::DoIdle
(00049A30) TNonVisualDataModule::SessionIdleTimerTimer
(003A4AC8) System::Classes::_18201
(00043519) USER32.dll
(00024047) USER32.dll
(00023199) USER32.dll
(00022F7B) USER32.dll.DispatchMessageW

(00F884B9) C5296_0
(00F89A93) _ReThrowException
(00071A5F) TEditorManager::CheckFileChange
(0006FA2A) TEditorManager::Check
(00018C78) TCustomScpExplorerForm::Idle
(00049A73) TNonVisualDataModule::DoIdle
(00049A30) TNonVisualDataModule::SessionIdleTimerTimer
(003A4AC8) System::Classes::_18201
(00043519) USER32.dll
(00024047) USER32.dll
(00023199) USER32.dll
(00022F7B) USER32.dll.DispatchMessageW

The problem happens rarely. I cannot reproduce it.