Failed to lauch

[:1]After todays Steam update my Supcom 2 won't launch.
The laucher starts, closes and restarts several times bbefore giving me error
"SUpreme commander 2 failde to lauch error code 51"
Where can I find error codes and what error is this?|||Have you tried running SupCom 2 as admin (by ticking the run as admin box in the compatibility settings) and/or running steam as admin?
If you have, have you tried turning off your AV?|||Also try deleting the Game.prefs file.|||Did both. Don't know wich one helped.
Thanks. :)