Using Steam. Got that “You are missing packages that are essential…” error after changing to a new computer. Tried Uninstalling / reinstalling a couple of times but only got that same message again and again. Then uninstalled FS2020 from Steam, uninstalled Steam from PC and then removed manually everything FlightSimulator and Steam related from hard drive - all the folders mentioned earlier in this thread. Restarted Windows. Installed Steam, installed Flight Simulator. WORKS!