<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 5.7.6

Error message:
Invalid%20access%20to%20memory.%0D%0A%0D%0AStack%20trace%3A%0D%0A%280067117C%29%20TTerminalQueue%3A%3AGetIsEmpty%0D%0A%28007E46BA%29%20C4799_3%0D%0A%28007E6722%29%20____ExceptionHandler%0D%0A%28007E369C%29%20__ExceptionHandler%0D%0A%280008A61F%29%20ntdll.dll%0D%0A%2800077E7A%29%20ntdll.dll.KiUserExceptionDispatcher%0D%0A%28000071F4%29%20TCustomScpExplorerForm%3A%3AAddQueueItem%0D%0A%2800011678%29%20TCustomScpExplorerForm%3A%3AExecutedFileChanged%0D%0A%280005A51D%29%20TEditorManager%3A%3ACheckFileChange%0D%0A%2800058758%29%20TEditorManager%3A%3AFileChanged%0D%0A%2800169E61%29%20Vcl%3A%3AActnlist%3A%3ATCustomAction%3A%3AExecute%0D%0A%28003402A8%29%20System%3A%3AClasses%3A%3A_18201%0D%0A%28000374F1%29%20USER32.dll%0D%0A%2800015C3B%29%20USER32.dll%0D%0A%280001553C%29%20USER32.dll%0D%0A%28000152FB%29%20USER32.dll.DispatchMessageW%0D%0A%0D%0A%28007E4D25%29%20C4799_3%0D%0A%28007E62FF%29%20_ReThrowException%0D%0A%280005A53F%29%20TEditorManager%3A%3ACheckFileChange%0D%0A%2800058758%29%20TEditorManager%3A%3AFileChanged%0D%0A%2800169E61%29%20Vcl%3A%3AActnlist%3A%3ATCustomAction%3A%3AExecute%0D%0A%28003402A8%29%20System%3A%3AClasses%3A%3A_18201%0D%0A%28000374F1%29%20USER32.dll%0D%0A%2800015C3B%29%20USER32.dll%0D%0A%280001553C%29%20USER32.dll%0D%0A%28000152FB%29%20USER32.dll.DispatchMessageW

Status: not_matched

The problem happens rarely. I cannot reproduce it.