It seems that something has gone wrong with a game on the Xbox 360(shocker), as reported first by Kotaku The problem seems to be coming from the the patch that was originally to stop freezing in the first place(I imagine that) But Ubisoft urges everyone to do these 6 steps to prevent this problem.
Steps to clear the system cache below.
1. Load to the Xbox 360 dashboard
2. Choose “System Settings”
3. Choose “Memory”
4. Highlight your hard drive
5. Press “y” for device options
6. from here just choose to clear system cache
Hope no one got a red ring for all of this.