Trying to create a new folder on the webserver and got this error. Tested to change the parent folder, trying to create a folder there, same issue. Restarted WinSCP everything is working.

WinSCP 5.9.3

Error message:
External exception C0000006

Stack trace:
(008651E7)
(0008147F) ntdll.dll
(0006F02A) ntdll.dll.KiUserExceptionDispatcher
(00014D55)
(0003781D)
(003B521C)
(0019C395)
(00373100)
(0002C2B1) USER32.dll
(0000D885) USER32.dll
(0000D1DF) USER32.dll
(0000CF9B) USER32.dll.DispatchMessageW

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.