why cant i play halo 3 custom games?

[kuch56]

i can play a custom game but if it is a player made custom game i cant play. im using the halo 3 mythic cd so i have all of the maps. but it wont let me play any games made by a player. it says that i am restricted to play player-made maps.. how do i fix this?

 

[Apotheosis001]

I think there is a allow user created content option somewhere.