No sooner than they released a patch for Fez, the game's creators discovered a game-breaking filesave corruption and warned everyone not to accept the title update. Microsoft has now taken the step of removing the patch altogether, meaning people who didn't get the memo about the patch won't find their game bricked by it.
Polytron, in an update on its blog, said it is working to deliver a fix as soon as possible -- "Like, in less than two months." They're being facetious. I hope.
Update Was Live [Polytron]