I have purchased all 4 DLC maps for halo 4, I can modify the in forge, but when I try to play in matchmaking, in the bottom of the screen it says: "Players do not have the necessary DLC maps" I have already deleted the latest update, and download it again, but still nothing.
Could you explain me why is that?
Have you also downloaded the free Forge Island map? There is actually 5 DLCs for Halo 4:
Crimson map pack - Harvest Wreckage and Shatter maps
Majestic map pack, Monolith, Skyline and Landfall maps
Castle map pack - Daybreak, Perdition and Outcast maps
Champions bundle/Bullseye map pack - Pitfall and Vertigo maps
If you are receiving the message stated then you are missing one of the above. Try downloading the missing DLC and try again to see if the message goes away. Also be aware that every player in the lobby MUST have the DLC for them to show up to vote. If just a single player doesn't have the DLC then the maps they don't have wont show for anybody. And with Halo 4 having a low population filled with mainly non DLC owners, chances of getting to play on DLC maps are very slim.