I am missing maps and weapons from Back to Karkand

Check the store option from inside the game. And worst case you might have to reinstall the game again. Don't think you will lose any of your MP stats. 

Tono wrote:

After the update I noticed that my weapons from Back to Karkand were missing, as well as some of my maps.  I went to the Xbox store and I can not find the maps Back to Karkand to redownload.  Any ideas of what I can do to fix this?

Is it fixed now?