I have EXACTLY the same problem, I flew for hours without problem yesterday, I had to quit by clicking on the ‘exit’ button I turned off the computer, an hour later I restarted and from there I only have CTDs whether I click on FLY or not, I haven’t modified anything, I tried a reinstallation, I emptied the community, I checked and everything is up to date, 2020 works without problem, this story is crazy, but reading your comments I feel less alone and I am reassured, the problem will be fixed I think… I read that this error already existed in 2020 so the problem must be known