Apparently a number of PlayStation 4 owners are having a serious issue with the system corrupting their save data, rendering their progress in the top PS4 titles unplayable. The problem being reported by some PS4 owners is labeled error CE-34878-0, and has become more prevalent in recent weeks. The error first started being reported back in Dec. on the official support forums for the system, but more and more players are complaining about receiving the error code lately.
The exact cause of the error is not yet clear, nor are the conditions required to trigger it. The problem seems to be related to the system and not the games; some have reported problems with Battlefield 4, others have had the issue with FIFA 14, and some say that their saves for NBA 2K14 no longer work...
Sony has not publicly commented on this issue and what is causing it to crop up on so many systems is unknown as of this writing.
We will have more on this story as it develops.