Hello,
A few weeks ago I downloaded the Champions bundle pack but unfortunately the two maps that come with it will not load. I try to load the maps in the Custom Games and Forge Lobby but a message pops up on the bottom of the screen saying “Players failed to load content. A player may be missing downloadable content”. I have tried deleting the DLC from my hard drive so I can download them again and clearing my system cache but I still have the problem.
Is there a solution to this?
mate I am having the exact same issue! it’s -Yoinking!- me off! Xbox support cant solve it, and I have basically wasted £4.09!
have you fixed it yet?
Nope, it still won’t work.
I have exactly the same problem as you!!!
I even went so far that I bought the Bullseye Pack also just to be sure to get it to work.
But NOOO!! Still gets kicked out.
Everything else works perfectly, it’s just Vertigo and Pitfall not working and I be kicked out. 
Have never had any problems with the xbox, and I have played since 2000. So it feels a little bit bad that you pay lots of money to Live, and various Map-packs and it will not work.
P.S. In my case, I bought twice for the same product, and it still not working! D.S.