I have tried getting the Classic Completion achievement in Halo Reach, yet no matter how many times I do it without using an armor ability the achievement will not unlock. I have unbound my armor ability key, I have done this mission without dying and using an armor ability, and I have done it on every difficulty.
I am going to assume you’re on Steam, if you’re not, I don’t really remember how to do this on the other storefront or Xbox.
- Disable Steam Cloud Syncing - Go to C:\Program Files (x86)\Steam\userdata<Your user ID>, make a backup of the 976730 folder, and then delete it. - Go to C:\Users<username>\AppData\LocalLow, make a backup of the MCC folder, and then delete it. - Try to get the achievement again. If you get it, you can restore your original folders and turn Steam Cloud back on.