Okay so as long as you dont break the chest open in camp the game doesn't corrupt. Although, I think it is still related to the chest.
I took the chest out of camp and broke it to complete the quest. I saved and loaded to test the corruption. When I loaded, the chest was BACK TOGETHER AGAIN and unable to be picked up, broken, opened, lockpicked, etc.
So when the chest was in camp trying to put itself back together, it corrupted the game.
This is 100% consistent and repeatable.