mattn

Looks like there's a permanent solution for the CTD immediately upon launch. According to the official forums, Asobo raised the issue with MS and now there's updates in the Windows Store for Gaming Services. I went into the windows store and hit "downloads and updates" in the top right menu. Nothing seemed to happen, so I clicked on Gaming Services and it initiated an update. I also updated xbox game bar and the xbox app too for good measure. I launched MSFS without touching Defender and it ran without CTD. I had not added an exception to Defender, and it was enabled after a fresh bootup. So look to see if you have the updated version of Gaming Services as per this screenshot.

Yes, I wish I had tried it BEFORE I re-downloaded 120gig to reinstall the sim :) From the official forums, quite a few people have had the issue and shutting down Defender seems to help most of them. Also, if you're on the MS Store version, once the install is done, you'll have to go into content manager and update a whole bunch of individual packages to get the latest content updates.

CTD immediately on launch (black window pops up, then disappears) has been common this week. Disable Windows Defender real-time protection and it should launch. You can also add MSFS .exe to the Defender exception list, but I haven't gotten around to doing that yet. Hopefully MS (not asobo) will fix this.