@Willfre4494 - good point with the Sysinternals Process Monitor.
I tired it, and with me it was similar: durching the BlackScreen MSFS was accessing the RollingCache and some kind of Sound.Init (?) space or routine.
For me the problem seem to be solved by applying the latest Windows 10 update (in this case ‘2021-08 update for Windows 10 vers. 21H1 : KB4023057’)
Update: This was only a temporary success: after the Windows update I was able to start the MSFS and install the WU6 Update including all scenery updates and executed a small circle in my vicinity and shutdown MSFS and my computer. This morning after reboot I am back at square 1 - the black screen of Doom. When I close MSFS, the desktop appears, but the flightsim process is not properly stopped (stilll visible in taSk manager). I have to logoff. When I start then again, I am prompted with a dialog: “MSFS not properly closed last time. Do you want to run in Safe mode or normal mode?” - also Safe mode just brings me to the black screen.
What an annoyence! Nothing is working, no proper error message!
When I opened a ZEN message I was advised of the following 3 topics discussing possible solutions to the “problems during start” issue:
https://flightsimulator.zendesk.com/hc/en-us/articles/4406047820690-All-versions-Sim-freezes-or-crashes-before-loading-fully
https://flightsimulator.zendesk.com/hc/en-us/articles/4406039624338-All-versions-Loading-issues-Checklist
https://flightsimulator.zendesk.com/hc/en-us/articles/4406047066770-All-versions-Stuck-on-a-black-loading-screen
- try Fast launch
- check sound output / use ‘spacial sound’
- run game as Admin
- unplug any USB device
- uninstall/install MS Gaming service
- apply all pending Windows update or any other MS Store update
- sign off and sign in again into MS Store/XBox app
- synchronize time settings
- remove the community folder
- disable the security and Antivirus software (not comment here from my side !)
- disable certain non Microsoft programs
Actually, the advice to disable non MS apps helped me: I disabled all and the MSFS did start. I enabled all previous non MS apps one by one and tried the flight sim - MSFS started all the time.
In the end all disabled non MS app were enabled again and MSFS did start up. (I had the suspicion, that the August update of Adobe Lightroom and its cloud is the cause. But all is running now.)
I am slightly confused about this procedure.
I will check again tomorrow again and see if something changes.