i use github and have successfully added and synched files on my laptop in the past.
as of recent i started getting \"PuTTY Fatal Error: Disconnected: No su
I got this error when using TortoiseGit to clone a repository from GitHub. Fixed by clicking "Load Putty Key" and selecting a key file (*.pkk) in the Git clone dialogue.
You can get plink & pageant from here: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
They are PuTTY tools.
TortoiseGit > Settings ... Network ... SSH Client: C:\Program Files\Git\usr\bin\ssh.exe
Location my vary. On one computer it was in C:\Program Files (x86)\Git\bin\ssh.exe
I had a similar issue after updating GitExtensions to version 3.3.0.7719
Somehow it reverted my authentication settings to use PuTTY instead of OpenSSH.
In that version here is the menu I used to enable OpenSSH again: