how do i get to play user created content on xbox 360 halo 3?

[a.hobnob]

when i play with friends most of the time it says one or more player in your party cant play because of user created content ... how do i make it work?

 

[robert f]

most the time you just have bad internet

 

[Duh]

Download the content that you are missing. Got to Marketplace in Halo and download it. Maybe it's a map that you don't have or a mode that you don't have.