As the title says, I changed my MOBO and CPU, I did an upgrade to an i5 13600k and when I click to start it starts for a sec and then off to desktop. MS Store version. Any solution?
I kind of had the same problem with the Steam version after upgrading my Mobo and CPU, but kept my old M.2 SDD with MSFS already on it.
In my case, the files and folders inside the “official” folder inside my game install directory were all gone. That seems to have been because I also reinstalled Windows, and the new Windows had no ownership of the files, so did not display them.
What I did was to boot the system from my old Windows installation, and made a backup copy of the whole “offical” folder, and then took ownership of the folder via the “properties → security” pane when right clicking the “official” folder. Thereafter, booting from my new Windows installation, the files were all there, and MSFS did start.
I had to do a complete windows reinstallation. Now I am Installing MSFS again and everything works as expected. But it is still strange. Never had such problems with any other game launcher. Anyway, Best side effect is, I have a clean Windows. 
Don’t know if it’s the same thing, but I replaced (added) a Radeon RX 6800 and disabled the on-board graphics and MSFS ended up wanting a complete reinstall from the “updates” screen - 13 hours worth - and all the world updates, etc. etc. etc.
Things are happy now, but I ended up having to re-activate both X-Plane and MSFS after the install.