If you downloaded the maps, but you cannot see them in-game, try this: go to dashboard go to system settings > memory select halo reach delete "Bungie Pro Confirmation" It doesn't get rid of your bungie pro, or affect you in any way. That should clear up your problems.
Failing that using the same method delete the noble map pack and then reinstall. B.Pro and Noble Map Pack mess up the Defiant map pack for some reason.
Have to bookmark this, since I have both the previous map pack and Bungie Pro. Thanks for posting this up.
Didn't you find out how to fix a similar issue with the Noble/one of the H3 packs as well? Tsb to the rescue .
I did back in H3 for one of them. The noble map pack didn't affect the defiant pack for me. Just try this first.
Didn't work. Deleted B.Pro confirmation, and the maps show up in-game, but I'm still getting a failed-to-load-content error.