Every time I try to connect to xbox live the game would freeze or give me a pop up error saying: sound bank failed to load mpl_common.english. You have a build problem.
Hmmm. Build error? Can you try the disc on a different console (probably your friend's console or in a local game shop perhaps). Build errors are caused by console issues. In case the game will work on a different console have your Xbox checked. In case it will not, try to re-update your game. To do that go to System Settings then to Storage. Select All Devices and then My Games and Apps. Go to BO2 and delete all the update for the game. Restart your console and launch the game again.
Just to give some info, those code-like thingy that you're seeing are files from the game that is not being read by your console. There might be an issue with the console's hard drive or whatever it was called to read the files of every game being played. With this, follow what the previous player provided and if the same thing did not happen on other console, then it's either you have your console fixed or replaced.
A support case was created for you and you should be contacted shortly by a Customer Support Representative, if you haven't been already. You can view and update your case at the Activision Support website. After logging in, go to "My Support" then "My Cases".
Just to add something up, try to also have your storage device be checked at. If you're using an external device for your game, try to switch to your Xbox's hdd and see what happens.