One of my chief complaints with Fez was how buggy it was. Thank God they released a patch to clean up the game! Oh wait...
UPDATE: BAD NEWS EVERYONE
There is an issue that seems fairly widespread where the save file can be seen as corrupted by the game after installing the patch. We're floored that this wasn't found in testing. For the moment, deleting your system cache should resolve the issue, but if that fails, there is no known workaround. We'll keep you updated on the situation.
You're floored? You're floored? What a joke. So don't play Fez everyone. Just don't bother. How do you replace never-ending death-loops and other game-breaking glitches with a bug that completely deletes the player's save game?