I had an open connection to a RuneAudio player (ArchLinux) and my PC fell in hibernation. When waking up I saw that the connection was lost (RuneAudio was offline!), and when I choose cancel, I saw "cancelling" and then the ERROR mentioned. This was the first time I saw the error, and this cancelling was used about 50 times until today, so it can be a unreliable bug...

WinSCP 5.13.5

Error message:
Invalid access to memory.

Stack trace:
(003F2A9F)
(00083FFF) ntdll.dll
(00071931) ntdll.dll.KiUserExceptionDispatcher
(00380EE0)
(00045359) USER32.dll
(00036297) USER32.dll
(000353D6) USER32.dll
(000351AB) USER32.dll.DispatchMessageW

(003F268C)
(00083FFF) ntdll.dll
(00071931) ntdll.dll.KiUserExceptionDispatcher
(00380EE0)
(00045359) USER32.dll
(00036297) USER32.dll
(000353D6) USER32.dll
(000351AB) USER32.dll.DispatchMessageW

Status: unknown_rel_addr

The problem happens rarely. I cannot reproduce it.