The Flight Sim not shutting down is an error mostly caused by the community folder: the Fly by Wire Airbus or the Working title Garmin G1000.
(Or the problem can be caused by any other half-compatible or outdated mod inside the community folder too, just remove a bunch of folders and see if the sim shuts down correctly, if not remove ten more folders and STRG + X and STRG + V them into a different location, and when the sim finally shuts down in a proper way test every single one of the last ten relocated folders to find the culprit.) 