My girlfriend and I have spent the last while playing Halo CE Anniversary, and as she signed in this morning, all of her save data including level progression and skulls found has been deleted, even though the data has remained untouched on the actual hard drive.
We didn’t turn off the console during loading or saving sequences, it’s just happened on its own accord. It was fine while she was offline, but then she connected to Xbox Live and suddenly she could only start a new campaign with her Grunt Funeral skull activated, that’s it.
Now, after clearing up my own saves a bit (hers remained untouched), I’ve lost all my campaign progress (My data was stored on Cloud, but for some reason it split it into two and so I deleted the Hard Drive save, so for some reason I can no longer choose which map I’d like to play on, everything else is intact. I’m not fussed about this though.