I'm getting disc read errors with Prototype 2 which mirror ones I had with Modern Warfare 3. Prototype 2 worked for a little bit, but then gave unreadable disc messages, the disc did appear to have a scratch on it so I sent it back for a replacement, but now the new completely clean and scratch free disc cannot be read either. I have tried the steps in the troubleshooter and the steps in the relevant post (clearing my cache, removing hard drive, etc.). I tried the prototype 2 disc in my friends' newer XBox slim and it loaded normally so it isn't the disc. My Xbox is still able to play non Prototype 2 and MW3 discs.