Hi Amy I had the same issue on the PS4. What I noticed is the first time I save a game it works fine (this includes autosaves) but after the first save any additional save will crash the game. What I was able to do is after every time I save or I see an autosave I would close the game down completely and re-open it. This is very tedious and be warned this is the only beginning of your troubles. Soon you will not be able to travel to Lucuala Forrest and the game will soon start crashing every time you talk to a vendor.
These are game ending bugs for the PS4 that have been known about for over two months since release. You should try to get a refund.
