last update on 11/25/12 has ugly glitch

i completed the campaign on legendary on co-op on 11/24/12 and it erased my saved file but my service record shows that ive completed it on legendary.

PLEASE HELP

Yes. We completed the game on legendary on co-op. He logged back in a couple of days later and the game notified him that something has been updated from 343. After that, he chose his memory like he would normally and once at the main menu, his saved file was lost.

I wish 343 would leave a running list somewhere in-game where you can view all the latest news and updates that were applied. That way, maybe we can specify a bit more about what update may have caused issues…

If anyone knows what to do, please let dannyf456 know. Thanks!

P.S.
We also called XBox on this, they weren’t much help. We tried doing some basic troubleshooting like redowloading his profile and checking connectivity to XBLA, but of course to no avail, nothing worked. He somehow lost his save file for his co-op campaign.