In some cases entries in the hosts file need to be removed:
If you have an antivirus, try to disable it temporally.
Have a look at this checklist:
https://flightsimulator.zendesk.com/hc/en-us/articles/4406047820690-How-to-troubleshoot-crashing-on-the-loading-screen-issues
Moved to User Support Hub > Install, Performance & Graphics that is more appropriate.