Halo 2 DLC disc worked on 360. Now it doesn't

A couple of months ago I bought a used Halo 2 DLC disc off of Amazon, so I could play all of Halo 2 maps. I installed the on disc H2 update and then the maps. My console was online when I did it, and XBL didn’t interfere. It worked. I only played with the DLC for a few days in a row before going back to Halo 4. Now, today when I fired up Halo 2, the DLC is nowhere to be seen. I checked my storage and it’s still there, but wont show up in the game. What happened? How can I fix it? Did an XBL update render it useless?

I see that you have the FOTUS armor for Halo 4 so I take it that you bought the Halo 4 console. If this is true and you did the data transfer from your old 360 to your new 360 this is root of the problem. DLC for Xbox 1 games will not transfer from one 360 to another one. All you have to do is delete the DLC you have now and re-download the DLC and update from the DLC disc and you should be fine.
Note: you do not have to delete your game saves, just the DLC!

Thanks, but I’m using H2 on my old console. However, I haven’t tried deleting and re-installing. I’ll try that tomorrow.