I, like some others on this forum, have the issue whereby if a 360 controller is plugged in when I launch FC4, I just get a black screen. I can alt-tab out and back in to the game, but as soon as the menu changes I will get another black screen. The game is unplayable unless I remove my 360 controller.
In doing some investigation, I made the following changes:
1 - disabled the 'Human Interface Device Access' service
2 - disabled the 'HID compliant game controller' device
Now when I run the game, the black screen problems are gone, but the controller no longer works. However other games - like Crysis 3 - can still detect and use the controller just fine.
So my hope is this information might be of some use to the developers - something about HID compliance or compatibility or something is interfering with Far Cry 4.