Just wanted to chime in with this, It seems there is a bug currently with the Unity Engine causing some players (running avast) to find there games abruptly ending. (being affected by this.) The Unity team has made a new mono.dll which should work with the game to fix/make the engine stable with Avast. http://forum.unity3d.com/threads/172759-Unity-4-0-1f2-and-avast-8-0-1482-quot-getThreadContextfailed-quot-error/page3 I think it’s worth mentioning to the developers so they can compile there games with this bug fix.