Certain maps on Halo 3 won't load. Help?

[Maddawg_2013]

The maps that won't load are a mix of map packs and the ones that come with the game. Is it my disc? Should I buy a new disc? Or is it something else? Please help!
It will go from 0% to 20% back and forth. Then it says, Player failed to load content

 

[Ian]

This happens to me sometimes, and I don't know why. Just go to the Bungie Marketplace and download them again. The download will complete instantly since you already have the maps, but for some reason it still fixes the problem.