In case you are a Steam users, and you are launching FarCry though Steam, than just use the following Fix:
1. Close your FarCry and Steam.
2. Right click on the Steam.exe -> Properties -> Compatibility Mode.
3. Tick the "Run this program as Administrator" box and click "Ok".
Now just Run Steam, and than launch FarCry. Normaly it should be fixed now.
Otherwise, just do the same on the FarCry.exe