I believe it had more to do with the completely bonkers admin. rights of Windows 10
Which has been screwed up by some other software, because I assure you that, by default, there are no problems whatsoever with Windows 10 and GSX, and Windows 10 is what we all at FSDT use nowadays.
I'm now getting this error:
ImportError: No module named common
This error seems to indicate you still haven't completed the installation correctly, since this file cannot be missing, since it's installed by the installer automatically,. so the only possible explanation left, is the installation is still not complete and has been blocked somehow.
Have you tried what I suggested to do ?
And tell to the utility to unlock the FSX\fsdreamteam folder, then REMOVE IT manually, reinstall whatever scenery you have and GSX.