Fatal: Server unexpectedly closed network connection

I've installed winscp version 4.1.8 and I had no problems.
However some days ago I always receive the error: 'Fatal: Server unexpectedly closed network connection' when connecting to a server.
On another PC there is no problem.

Please post a full log file showing the problem. To generate log file, enable logging and log in to your server. Note that passwords and passphrases not stored in the log. You may want to remove other data you consider sensitive though, such as host names, IP addresses, account names or file names (unless they are relevant to the problem). If you do not want to post the log publicly, you may email it to me. You will find my address (if you log in) in my forum profile. Please include link back to this topic in your email. Also note in this topic that you have emailed the log.

Docs did not help solve the issue I am having. I have done further investigation. The program works fine from our XP boxes. We just encounter the error on Vista. Anyway, the latest version of FileZilla has the same issue on Vista but if I back up to version 2.2.22 of FileZilla it works. I don't know if this helps or not. I plan on trying WinSCP from a non company Vista PC at home to make sure I'm not running into some firewall or other security infrastructure issue that is out of my control.

I also have the capability to output wire traces using WireShark if that could help.

mccorb wrote:

Docs did not help solve the issue I am having. I have done further investigation. The program works fine from our XP boxes. We just encounter the error on Vista. Anyway, the latest version of FileZilla has the same issue on Vista but if I back up to version 2.2.22 of FileZilla it works. I don't know if this helps or not. I plan on trying WinSCP from a non company Vista PC at home to make sure I'm not running into some firewall or other security infrastructure issue that is out of my control.

Let us know if you find anything. BTW, I believe that you have posted in worng thread.

Hello,

I encountered same issue.

I can established SFTP using WINSCP 5.5.6 from a Windows Server 2012 (Server F) to a Appliance SFTP Server. But i cannot connect established SFTP from other server (Server E). Below are the logs:

. 2016-12-06 09:45:21.460 Looking up host "172.21.1.87"
. 2016-12-06 09:45:21.460 Connecting to 172.21.1.87 port 22
. 2016-12-06 09:45:21.522 Server unexpectedly closed network connection
. 2016-12-06 09:45:21.522 Knocking FTP port.
. 2016-12-06 09:45:23.534 FTP port did not open.
* 2016-12-06 09:45:23.581 (EFatal) Server unexpectedly closed network connection.

Any recommendations? Thank you!

badonson wrote:

I encountered same issue.

I can established SFTP using WINSCP 5.5.6 from a Windows Server 2012 (Server F) to a Appliance SFTP Server. But i cannot connect established SFTP from other server (Server E).

Can you connect from the Server E using any other SSH/SFTP client?