Go through each of the following steps one at a time. Copy each line, one at a time , paste it into Power shell (Admin rights)…
and it will then run. Wait until each runs and finishes before you move on to the next one.
When you are completely finished, Restart your computer and then try to see in MS2020 will start and run properly
Dism.exe /online /Cleanup-Image /checkhealth
Dism.exe /online /Cleanup-Image /scanhealth
Dism.exe /online /Cleanup-Image /Restorehealth
sfc /scannow
Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
Dism.exe /Online /Cleanup-Image /StartComponentCleanup
RESTART your computer as the last step. Then go for a test flight.