FSX Crashes after "End Flight" with REX Weather Engine

During the flight, FSX is fine, and I am running FSX with the REX 2 weather engine. But when I end a flight (press Esc and click "End Flight") when FSX goes to the main screen, there is a "fatal error" and FSX no longer responds. I am 90% sure this has something to do with the REX weather engine, because this only happens when it is running. Of course it's okay if no one know the answer to this problem, because my flight is over and I was about to exit anyway, but it is very annoying.