with a bit luck, we get a more detailed info why it crashs ( not often, but sometime )
Just searching for the ERRORs related to Flightsimulator and post the message from General-Tab EXAMPLE
I also tried to check what the app do near that 80%, in online-mode .. it loads some online data. So also recheck that all anti-vir, firewalls, etc. are stopped for the test… its a guess, but who knows.