<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 5.9.4

Error message:
Ошибка доступа к памяти.

Трассировка стека:
(000EEE38)
(00866B5E) C5073_0
(00868BC6) ____ExceptionHandler
(00865980) __ExceptionHandler
(00046186) ntdll.dll.RtlRaiseStatus
(00046012) ntdll.dll.KiUserExceptionDispatcher
(0063E07D) _ssh2_fingerprint_blob
(0063E172) _ssh2_fingerprint
(00624042) _ssh_agent_forwarding_permitted
(00629ABF) _sshfwd_x11_is_local
(00629E47) _sshfwd_x11_is_local
(0061D20E) C2447_0
(0061D3C1) C2447_0
(0061D6DC) _ssh_connshare_log
(0064C0F9) _select_result
(006FE8C7) TSecureShell::HandleNetworkEvents
(006FEB8A) TSecureShell::ProcessNetworkEvents
(006FE17B) TSecureShell::WaitForData
(006F9585) TSecureShell::Init
(006F8E5A) TSecureShell::Open
(0076FF7A) TTerminal::Open
(006C8C3F) TTerminalThread::TerminalOpenEvent
(006C3C14) TSignalThread::Execute
(00098B63) Userinterface::C20_0
(00052C43) kernel32.dll.BaseThreadInitThunk
(000627F3) ntdll.dll
(000627C3) ntdll.dll

(008671C9) C5073_0
(008687A3) _ReThrowException
(006F9693) TSecureShell::Init
(006F8E5A) TSecureShell::Open
(0076FF7A) TTerminal::Open
(006C8C3F) TTerminalThread::TerminalOpenEvent
(006C3C14) TSignalThread::Execute
(00098B63) Userinterface::C20_0
(00052C43) kernel32.dll.BaseThreadInitThunk
(000627F3) ntdll.dll
(000627C3) ntdll.dll

(008671C9) C5073_0
(008687A3) _ReThrowException
(006F972E%

The problem happens rarely. I cannot reproduce it.