Teofilo's post mentioned, " it was working perfectly before today's update.." I am assuming the "update" he is referring to is the regular Windows update. When strange things start happening to my "Sim" programs, I have found through long and arduous trial and error that the nasties occur when a new Windows update comes down the line. I uninstall the Windows update and then check program functionality. If the problem was the update, I test run the Flt Sim and ATC type interactive sims. If everything is back to normal, I create a restore point with a title, such as: "All ok 11/24/19. If crazies happen again, I restore the "safe" restore point. This procedure happens every month or two and helps me keep my sanity.
A value judgment needs to be made if you do not install the latest Windows update. Security issues might jeopardize your system performance. Take precautions as needed. - Nick