It's possible that another add-on that you start with the sim that is not fully compatible with current Windows standard ( for example because it tries to write something in Program Files ) is wrongly setting some Compatibility setting to the sim that should not be set, which will cause the sim to run AS IF it was using something like Windows XP, which in addition to cause issues with our software, that is fully native Windows 10, is also slowing down your sim, forcing video drivers to run in a lesser performance mode and because of many Windows API calls being intercepted by the compatibility mode.
Our Updater detects the damage such add-on do to your installation, so it RESET every compatibility mode wrongly set to the sim ( except Administration mode, which is required by some add-ons ), which explains why the scenery initially runs after you ran the updater but then, when you exit the sim, the wrong compatibility mode which has been set, will be back again on the next session, so you are mislead thinking you must run the FSDT updater again, which is not normally the case, except the fact is trying to fix your sim.
In other cases, it's also possible that Windows itself might set a compatibility flags by itself, sometimes just because the sim crashed ( these are not easily found, since they are stored in the registry ), and yes, our updater detects that and fixes that too.
