Cannot connect to SFTP server via .Net (Network error: Connection refused), but using GUI works

Hi,

There is a SFTP server I need to connect to, using username and password. I can connect to it using the GUI, but I cannot using the .Net assembly. I get a 'Network error: Connection refused'. Attached should be all the relevant information. The SFTP server is only using SFTP-3, so I even tried using SessionOptions.AddRawSettings("SFTPMaxVersion", "3");. The SFTP owners say they do see successes in their logs, but only when I use the GUI. The failures come up as using port 21. My logs do show that after SFTP fails, it knocks the FTP port. They don't state at what point it fails, and my logs do not show this either.

Any suggestions to fix this?

Thanks

Please attach a full (unobfuscated) session log file showing the problem along with log of a working GUI session (using the latest version of WinSCP).

Attached are the logs.

I'd say that the UserCustomServices account does not have an access to network allowed.

Try to run the code using the same account you use for GUI (Administrator).