SSH Terminal Closes After Logging In...
I'm using Ubuntu Server 13.10. Everything has been fine until I started adding users to groups. The user will open Putty in Windows, connect to the server, enter username and password, and Putty immediately closes. Suspecting a potential Putty issue I rebooted and no change.
I created a custom group called sftp and added myself to that group. After that I was no longer able to SSH in due to the above explanation. I was able to log in locally to the server, but not SSH. So I removed myself from the sftp group and whola, I was able to log in again via SSH.
I've checked the /etc/passwd file for nologin on users, and that's not the issue. This also occurs if I add a user to built-in ftp group. I have checked /var/log/auth.log and it only says the user successfully logged in, never shows anything about the disconnect right after logging in.
Any advice would be helpful!