im having a similar problem but with a different message, the game is telling if i want to save my file i have to delete other save files but there is no longer any of the files (not even the 2 backup files for this save or my other save) whenever i go to load, save or save as.
i think the console game needs a ton of work as I've had this problem before losing a save i was 6 years into and know its happened to others and despite complaints being sent in no update has fixed this