<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 5.17.8

Error message:
External exception C000001D

Trace de la pile :
(00408778) System::Character::_16412
(000861AF) ntdll.dll

Status: all_insignificant

The problem happens rarely. I cannot reproduce it.