This issue has been added to the tracker:
https://winscp.net/tracker/1845

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<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 5.17.1

Error message:
Invalid access to memory.

Stack trace:
(00BEB8AD) _ssh2_serverside_agent_open
(00F84E6A) C5296_3
(00F86ED2) ____ExceptionHandler
(00F83C8C) __ExceptionHandler
(00087D7F) ntdll.dll
(00073221) ntdll.dll.KiUserExceptionDispatcher
(00BE9FEF) _ssh2_connection_new
(00BEA1E4) _ssh2_connection_new
(00BFD015) _ssh_ppl_free
(00BCBB8A) C2603_0
(00BCBC7D) _run_toplevel_callbacks
(00D05474) TSecureShell::EventSelectLoop
(00D04357) TSecureShell::WaitForData
(00CFF315) TSecureShell::Init
(00CFEC55) TSecureShell::Open
(00D86BB5) TTerminal::Open
(00CBE833) TTerminalThread::TerminalOpenEvent
(00CB9790) TSignalThread::Execute
(000BBE8F) Userinterface::C20_0
(00015357) KERNEL32.DLL.BaseThreadInitThunk
(00066B72) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00066B3F) ntdll.dll.RtlGetAppContainerNamedObjectPath
Authentication log (see session log for details):
Using username "1431-OrthoOneB".
This channel would exceed the server's total limit for sessions with processes. Please try again when the server is less busy.

Authentication failed.

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.

<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 5.17.2

Error message:
Invalid access to memory.

Stack trace:
(00BEB9E1) _ssh2_serverside_agent_open
(00F85292) C5296_3
(00F872FA) ____ExceptionHandler
(00F840B4) __ExceptionHandler
(0008403F) ntdll.dll
(00071941) ntdll.dll.KiUserExceptionDispatcher
(00BEA123) _ssh2_connection_new
(00BEA318) _ssh2_connection_new
(00BFD149) _ssh_ppl_free
(00BCBC36) C2603_0
(00BCBD29) _run_toplevel_callbacks
(00D05668) TSecureShell::EventSelectLoop
(00D0454B) TSecureShell::WaitForData
(00CFF509) TSecureShell::Init
(00CFEE49) TSecureShell::Open
(00D86F65) TTerminal::Open
(00CBEA27) TTerminalThread::TerminalOpenEvent
(00CB9984) TSignalThread::Execute
(000BBE8F) Userinterface::C20_0
(0001F417) KERNEL32.DLL.BaseThreadInitThunk
(0006562B) ntdll.dll.RtlGetAppContainerNamedObjectPath
(000655F8) ntdll.dll.RtlGetAppContainerNamedObjectPath
Authentication log (see session log for details):
Using username "root".
WARNING: Unauthorized access to this system is forbidden and will be
prosecuted by law. By accessing this system, you agree that your actions
are monitored and recorded.


Authentication failed.

The problem happens rarely. I cannot reproduce it.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<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 5.17.2

Error message:
Ошибка доступа к памяти.

Трассировка стека:
(00BEB9E1) _ssh2_serverside_agent_open
(00F85292) C5296_3
(00F872FA) ____ExceptionHandler
(00F840B4) __ExceptionHandler
(00087D7F) ntdll.dll
(00073221) ntdll.dll.KiUserExceptionDispatcher
(00BEA123) _ssh2_connection_new
(00BEA318) _ssh2_connection_new
(00BFD149) _ssh_ppl_free
(00BCBC36) C2603_0
(00BCBD29) _run_toplevel_callbacks
(00D05668) TSecureShell::EventSelectLoop
(00D0454B) TSecureShell::WaitForData
(00CFF509) TSecureShell::Init
(00CFEE49) TSecureShell::Open
(00D86F65) TTerminal::Open
(00CBEA27) TTerminalThread::TerminalOpenEvent
(00CB9984) TSignalThread::Execute
(000BBE8F) Userinterface::C20_0
(00015357) KERNEL32.DLL.BaseThreadInitThunk
(00066B72) ntdll.dll.RtlGetAppContainerNamedObjectPath
(00066B3F) ntdll.dll.RtlGetAppContainerNamedObjectPath
Протокол авторизации (подробности см. в журнале соединения:
Использую имя пользователя "okhrymen".

This system is for the use of authorized uses only.
Individuals using this computer system without authority,
or in excess of their authority, are subject to having all
of their activities on this system monitored and recorded
by system personnel.

In the course of monitoring individuals improperly using this
system, or in the course of system maintenance, the activities
of authorized users may also be monitored.

Anyone using this system expressly consents to such monitoring
and is advised that if such monitoring reveals possible evidence
of criminal activity, system personnel may provide the evidence
of such monitoring to law enforcement officials.


Аутентификация не пройдена.

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.

<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 5.17.2

Error message:
Invalid access to memory.

Stack trace:
(00BEB9E1) _ssh2_serverside_agent_open
(00F85292) C5296_3
(00F872FA) ____ExceptionHandler
(00F840B4) __ExceptionHandler
(0008403F) ntdll.dll
(00071941) ntdll.dll.KiUserExceptionDispatcher
(00BEA123) _ssh2_connection_new
(00BEA318) _ssh2_connection_new
(00BFD149) _ssh_ppl_free
(00BCBC36) C2603_0
(00BCBD29) _run_toplevel_callbacks
(00D05668) TSecureShell::EventSelectLoop
(00D0454B) TSecureShell::WaitForData
(00CFF509) TSecureShell::Init
(00CFEE49) TSecureShell::Open
(00D4E8F3) TSFTPFileSystem::Open
(00D88DD7) TTerminal::Reopen
(00CBEA35) TTerminalThread::TerminalReopenEvent
(00CB9984) TSignalThread::Execute
(000BBE8F) Userinterface::C20_0
(0001F417) KERNEL32.DLL.BaseThreadInitThunk
(0006562B) ntdll.dll.RtlGetAppContainerNamedObjectPath
(000655F8) ntdll.dll.RtlGetAppContainerNamedObjectPath
Authentication log (see session log for details):
Using username "dthoen".
This channel would exceed the server's total limit for sessions with processes. Please try again when the server is less busy.

Authentication failed.

The problem happens rarely. I cannot reproduce it.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

<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

Error message:
Invalid access to memory.

Stack trace:
(00BEB8F5) _ssh2_serverside_agent_open
(00F85D26) C5296_3
(00F87D8E) ____ExceptionHandler
(00F84B48) __ExceptionHandler
(0008402F) ntdll.dll
(00071931) ntdll.dll.KiUserExceptionDispatcher
(00BEA037) _ssh2_connection_new
(00BEA22C) _ssh2_connection_new
(00BFD05D) _ssh_ppl_free
(00BCBBE6) C2603_0
(00BCBCD9) _run_toplevel_callbacks
(00D06584) TSecureShell::EventSelectLoop
(00D05467) TSecureShell::WaitForData
(00D00425) TSecureShell::Init
(00CFFD65) TSecureShell::Open
(00D87CC5) TTerminal::Open
(00CBF943) TTerminalThread::TerminalOpenEvent
(00CBA8A0) TSignalThread::Execute
(000BBE7F) Userinterface::C20_0
(0001F417) KERNEL32.DLL.BaseThreadInitThunk
(0006562B) ntdll.dll.RtlGetAppContainerNamedObjectPath
(000655F8) ntdll.dll.RtlGetAppContainerNamedObjectPath
Authentication log (see session log for details):
Using username "root".
WARNING: Unauthorized access to this system is forbidden and will be
prosecuted by law. By accessing this system, you agree that your actions
are monitored and recorded.

Access denied.

Authentication failed.

I know how to reproduce the problem or the problem happens frequently enough. I wish to be contacted by the WinSCP team to help resolving the problem.