If misery loves company I'm here. My installation has had similar issues for some time now and I thought it was only my system. What helped me get in the air was only use C&D starts. Runway TO with engines running guarantees failure. Don't take off from addon airports; i.e., Community Folder installs.
That's the best I've come up with so far. Oddly enough, once it's flying I can land at addon airports without issues. I have no idea what's going on.
I've had MSFS for a year and all this started after update after update after update . . . ad nauseam.