Same Problem. ucrtbase-409- online and also offline 
Have buyed a new PC. Only W10, without any other software, no virusscanner, no msfs mods.
Only the os and the msfs2020 (naturally latest drivers and firmwares)
My ctd happens when iĀ“m click on the āgeneral optionsā - otherwise the game is running (longest test-2,5h without problems)
Have installled the eng language package and latest visualC++
De-and reinstall msfs -same problem
i despair