<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>

I was just downloading files in batch. I have done so before without getting this error. The only thing that could perhaps be different this time, was that the amount of files was considerately more (several hundred) and the total file size was bigger (300-500MB per directory). I had about 5-6 directories in the downloading queue. I also did not notice that anything actually went wrong. I got the error message, but as far as I could see everything downloaded (and deleted) correctly.

<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.7

Error message:
Invalid%20access%20to%20memory.%0D%0A%0D%0AStack%20trace%3A%0D%0A%28007E0326%29%20%0D%0A%2800081D3F%29%20ntdll.dll%0D%0A%280006F8EA%29%20ntdll.dll.KiUserExceptionDispatcher%0D%0A%2800674AE7%29%20%0D%0A%280000715B%29%20%0D%0A%280000C57D%29%20%0D%0A%280000CFB0%29%20%0D%0A%280000D037%29%20%0D%0A%280003229E%29%20%0D%0A%2800382614%29%20%0D%0A%280016A155%29%20%0D%0A%280034059C%29%20%0D%0A%280002C2B1%29%20USER32.dll%0D%0A%280000D885%29%20USER32.dll%0D%0A%280000D1DF%29%20USER32.dll%0D%0A%280000CF9B%29%20USER32.dll.DispatchMessageW

Status: not_matched

The problem happens rarely. I cannot reproduce it.