<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:
Error occurred during logging. It's been turned off.

Out of memory

Stack trace:
(003B480C)
(003B480C)
(003B493D)
(003272BF)
(006CA9A8)
(006CAAE8)
(00713236)
(00079C0D)
(00014C47)
(000379EB)
(000379A8)
(003402A8)
(00007731) USER32.dll
(00007811) USER32.dll
(000079C8) USER32.dll
(00007A0B) USER32.dll.DispatchMessageW

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.