How can I get all of the REQUIRED maps for Halo 3 on Xbox Live?

[corny#73]

It says I don't have one or more of the maps needed to play in this playlist. What do I do?

 

[hardynoob]

well, if you dont have the heroic map pack go download it, its free, and its mandatory for you to play, so that should help. if you did, then maybe download the map Cold Storage its free too. If thats not the case either then you probably dont have the legendary map pack, which you have to pay for. but most people dont really have it either, cause it will be free soon. If you have already done all of this then i have no idea how to fix your problem.