I have found a possible reason for the infamous Fatal Error UE4.
I use several monitors for gaming. MCC runs on my TV and that’s how I have it set up in the MCC settings.
But when I deactivate the TV as a display, the problems start.
When I start MCC, I get this error. But as soon as I activate the TV as a display again, the game starts normally.
I think this can help a lot of people and maybe 343 can do something so that people are spared from this error in the future.