ARMA 2 failed to start (error code 51).

I just finished downloading ARMA 2 from Steam but when I try to launch it I get a message saying "ARMA 2 failed to start (error code 51)." I've tried verifying game cache and updating my DirectX but nothing helps. I've also tried running the arma2.exe in the /steam/steamapps/common/arma 2 folder but that gives me an "Application load error 3:0000065432."

I've previously installed the demo and the demo works fine. Deleting the local content and re-downloading everything isn't an option as my Australian internet is incredibly slow and I don't have enough monthly download limit left for another ARMA2 download.

EDIT: Steam fixed itself, no more problem.