I was just about to give up on MSFS. Constant CTDs, sometimes random but most often at the start of a flight just as or just before hitting the “Fly” button. I had 60 hours on the game according to steam and 90% of that was downloading, re-downloading, changing settings and looking for the right configuration so I could play for more than 15 minutes. Updated drivers, removed all overclocks (actually underclocked CPU/GPU), put settings on low detail, nothing helped.
Finally I found my silver bullet: virtual memory aka pagefile.
My virtual memory was originally set appropriately at about 16 GB (I have 16 GB physical mem). I increased it by quite a bit (there are a lot of recommendations on what your virtual memory should be and I encourage you to read several opinions). IN ADDITION, I also turned on page file for my D: drive where MSFS is installed (windows on C:). Ever since I did that, not one CTD!!! I’ve even returned to my overclock on CPU/GPU and I’m playing for hours at a time and now shutdown MSFS when I want to ;).
I want to share this because it is not one of the solutions that I see emphasized much. I hope this helps someone.
Ryzen 1700x --now able to overclock to 3.7 GHz
Radeon 580 --now able to overclock to ~1450 Mhz
16 GB (2933 MGhz)-- now able to overclock to 3200 Mhz
Samsung 970 EVO C:/ 256 GB M.2
Samsung Pro 850 D:/ 500 GB (game install)
Honeycomb Flight Yoke
Logitech Flight Rudder Pedals
Playing MSFS on HIGH settings @ 1080P (25-35 fps) successfully for about 1 week. Thinking about moving to HIGH setting at 1440p.