How do i play 16 players on halo 3, cause it says the player didnt unlock the map?

[Andy D]

Halo 3, Xbox 360 LIVE, um...8v8 players, when i try, theres only 6 players, wth?

 

[menellus]

that means someone doesnt have that mappack, try playing on a map like Valhalla or Santrap. Or, make sure every one has downloaded the heroic map pack, its free to download now.