I’m not entirely sure if this has been posted already or not, but recently games on Halo CE haven’t been counting for the MP3 Player seasonal challenges. I don’t know why this change was made, but I personally do not like it. I really enjoy Halo CEs multiplayer, and this season just added all those cool weapon and vehicle skins that I won’t be able to see now if I want to get my progress on those challenges. I hope this is something that will be fixed soon.
It got removed because of a bug that affected the progress of multiple challenges. Basically they weren’t counting Halo: Combat Evolved matches.
There was a bug that didn’t allow it so they removed it entirely for some challenges while they fix it.
It was removed like 6 weeks ago, so don’t hold your breath.
They are working on it. There are quite a few bugs still with the challenge system so gotta be patient for them to roll out with a fix. Odds are they will roll out a big patch to fix multiple issues instead of just small ones for individual issues.