Found the solution (xBox 360) for BF4 game:
I deleted my user data from the hard drive, and then booted up the game again. I was then prompted to sign into my EA account again.
My user data is/was all backed up server side as well as on battlelog.
The only problem with this method is/was, you will probably have to set up all your loadouts again. But better having to do it only ONCE more than having to do it EVERY time you play the game.
Hope that helps you!
For some people it worked. I exhausted their fixes and they had to have "Experts" undo it. Logged on this morning and they actually fixed it.
