<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 5.15.4

Error message:
Invalid access to memory.

Stack trace:
(002B7EB0)
(0006248E) ntdll.dll

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.