I like many have game breaking errors with Undead Nightmare. However after testing out a method that may help some I have found that for the Xbox360 Undead Nightmare if you are playing the Game of The Year edition the game is just about unplayable with the latest update. However I also own the stand alone e edition of Undead Nightmare which for whatever reason with the same update the game is very much playable. There still are minor errors like every now and then a freeze or two, missing heads etc. However the game does not get stuck in walls, frozen on walls etc. The game is basically unplayable for me when it comes to game of the year edition. So if you are interested I have seen Undead Nightmare complete with map and everything used for as low as 8 dollars on eBay, and amazon. I actually am working on a hundred percent for Undead nightmare, and if it was not for my stand alone copy I would not be able to even play a few missions in the current state that Undead Nightmare is on for the game of the year addition. The sad part is I am sure all that is needed from Rockstar is a minor update but like many on this great forum have already stated Rockstar is too busy apparently on GTA5, which is really sad to me. I hope this helps some out there. Undead Nightmare is a awesome e game that really should be played threw by all Red Dead fans like myself.