Anti-cheat campaign and bugged epilogue

At the end of Pillar of Autumn, I hid behind the MAC gun until the ship was in position to be killed. I jumped up and successfully hit it. However, the anti-cheat system tagged twice. I wasn’t cheating. I posted the screenshot. The game booted me back to the menu, won’t load the epilogue, and I didn’t get the achievement for completing it. This was a Legendary run by the way. The mission selection says I beat it on Legendary but I still don’t have the achievement and I can’t load the Epilogue to finish the game.

I got the same problem, the anti-cheat pops up in the upper right corner of the screen, and I only need Pillar of Autumn and Lone Wolf on legendary to get the achievement for legendary run.

I’m having the same problem. At the end of Pillar of Autumn the anti-cheat came up and I was really confused and Epilogue wont even Load properly. Lone Wolf seems to run just fine though. Please Fix (MCC for PC)

I am also having the same problem, I noticed it first during the cut-scene at the end of “the package”. It referenced an unknown map file. I now cannot even load “Pillar of Autumn” on Legendary without getting booted to the main menu.

Update:
Upon further inspection, my steam files had become inconsistent (maybe due to the halo 2 update?) Following the instructions on the link below helped me fix the issue:

Same problem.

Make sure and file a bug report about this on the Halo Support site: https://aka.ms/HaloSupport

Be sure to read over the known issues list first before reporting