Diablo 3 Error 3000

So, you've received a Diablo III Error 3000 and now have no idea what to do. Well, this is what it officially means:

ERROR 3000: EXCEPTION NULL POINTER - GAME CLOSE

So we don't know much about it except that it happens when you click too fast and the game gets confused as to what you wanted to do. This only happens in Diablo 3 Beta.