Starting from the first dlc, autosave became buggy. Everytime it autosaves if you don't do any action the game doesn't crash, but if you try to move or press a button it will crash.
So i have the simple solution for you: disable the autosave feature while you investigate the problem, or make it optional.
Over my 270 hours of play i have always to keep my right eye peeled for the autosave symbol, while the other watches what's happening on the rest of the screen.
Do a patch asap for the autosave feature as i suggested pls.