This happened to me Saturday night on the PS4 (8/16/20). I even posted about it but not single soul has helped me.
https://answers.ea.com/t5/Technical-Issues-Consoles/PS4-GALLERY-DELETED-EVERYTHING/td-p/9413607
absolutely do not save the game when this happens!
If you’re on PlayStation what you’ll want to do is go to the game. Don’t click on it to load hit options. Upload/Download Saved Data
find the most recent “My Library” save and download it to the system. (Do not download anything else and make sure the My Library save is not when the crash happened or you will lose everything)
the save must be prior to the crash
I cannot tell you how to do this on Xbox but I imagine it is similar to PlayStation or every computer as you need to redownload the my library file.
Make sure you are saving often and uploading to storage (ps4) if you’re on Console
I have found that this happens when I download things to my gallery that I don’t realize is cc. My whole game crashes. Hope this helps!
