Solved
The "disable fullscreen optimization" option does not work on BF4 at all?
Sometimes I accidentally switch to Chinese IME and then the game quits fullscreen. Disabling fullscreen optimization should help with the problem and it does work on BF1 but not on BF4.
@coppercn Never fixed a issue like this but first thing to come to mind is BF4 my Documents worth a shot....
C:\Users\your PC Name\Documents\Battlefield 4
BF4 folder in my documents holds game configs and screen shots even if BF4 is installed on different drive. When you uninstall BF4 it does NOT remove this folder. So when you install the game again you can still have the same issues. Even if its not a new install it is still worth trying as the game cfg could be mucked up.
1- Go to my Documents and remove BF4 folder place it on your Desktop for now.
2- Be warned you do have to set up your in game settings again.
3-Repair BF4
4- When done go test your game. If it fails reboot your PC and run repair game again and test BF4.
