What causes it, is a mystery and whatever is clashing with GSX will be (almost) impossible to find out because almost everything nowadays are using simconnect in one way or the other.
That's just because you are still assuming the problem is *caused* by GSX, when it's likely GSX is the victim here, not the cause.
So, instead of disabling all the other addons, and leave GSX in place, which I'm sure will result in the sim shutting down properly (as it does for everybody else), you uninstalled GSX, which of course wouldn't really fix your problem, since you'll never know what the cause what in the first place.
So, what you should do, instead, is what I've said:
- Leave GSX installed
- Disable ALL the other addon modules. NO NEED TO UNINSTALL ANYTHING. Just disable them TEMPORARILY.
You can disable an addon either from the Options->Add-ons menu (if it's a good add-on that uses the proper add-on.xml method), so it's very easy to disable it OR you can disable addons that still use the legacy DLL/EXE.XML methods, by setting this line:
<Disabled>True</Disabled> ( it's normally False )
in all the 4 .XML files that controls such addons, which are located here:
%APPDATA%\Lockheed Martin\Prepar3d v4\DLL.XML
%APPDATA%\Lockheed Martin\Prepar3d v4\EXE.XML
%PROGRAMDATA%\Lockheed Martin\Prepar3d v4\DLL.XML
%PROGRAMDATA%\Lockheed Martin\Prepar3d v4\EXE.XML
You must check all 4 files.
This, of course, it's ONLY A TEST. I'm not suggesting you should stop using all your addons, but this is the only way to:
- Verify that GSX is not preventing to quit the sim
AND
- Being able to proceed by exclusion to find the cause, because now you can re-enable each module, ONE BY ONE, test, exit, try again, until you'll eventually find which one is conflicting.