<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 5.15.1

Error message:
External exception 80000101

Stack trace:
(F775AC89)WinSCP.exe
(00066086)ntdll.dll
(00066481)ntdll.dll
(0006873D)ntdll.dll
(00068B56)ntdll.dll

Status: all_insignificant

The problem happens rarely. I cannot reproduce it.