once you get logged in, you can always try starting up your program through the back door...
(1) login successfully as root or user to RDP
(2) as the same user that's logged in, in putty, run `ps -ef | grep -E ':[0-9]'` and find the number after the colon
(3) run `export DISPLAY=:123` where `123` is the number you found in step 2
(4) run `mono-sgen Whatever.exe` (in putty)