Valhalla doesn't load

I’ve had been trying to load Valhalla all day so I can get the elder signs achievement. I have about 75% of the map loaded, and it’s frozen. I have tried restarting my xbox, and tried redownloading the entire game (4 hours). Nothing seems to fix this issue. Now, it’s a day later, and I still can’t get in.
Thinking it’s just that map, I tried to load a game in The Pit, same problem. Do I not get Halo 3 multiplayer with this collection. I didn’t realize that I could not play one of the 4 games on the disc. I thought this had all 4 of the games on it, not just 1, 2 and 4.

It could be a problem with your disk.

None of my halo 3 maps are loading either

edit: I just unplugged my Xbox for 30 seconds and restarted and I was able to load up halo 3 in a custom game with no problem. I suggest doing this if you haven’t already.

Thanks to Myserio! not sure the reason, but unplugging for 30 seconds and restarting did fix it.