I was in the middle of the game when got first popup: "Sorry, something went wrong. We're working on it and we'll get it fixed as soon as we can". I choose Go Back option and my game start to loading. Two gray screens and then: "Service Unavailable". After few more refreshings I was able to go back in the game. As for now that is happening in Mafia Wars game. If anybody has the same problem and in different game do not panic, you will be able to play after refreshing. At this moment Facebook is working on fix or fix problems already.