then I could click Cancel och Allow. Stupid as I am by mistake I pressed "Don't allow, never show this message again", when I was going to choose "Allow, never show this again".
Uninstall GSX and be sure you reply YES to the questions "Do you want to remove the Addon Manager?" and "Do you want to remove the Couatl engine?" that are made at the end of the uninstall process. Be sure you reply YES to BOTH questions.
Then, go to the Control Panel, under "Internet Options", look for the "Content" tab, there should be a "Publishers" button, that will list the software publishers that you trusted, and another tab with untrusted publishers. If you see "Virtuali s.a.s", remove it from both tabs (especially if it's under untrusted)
Finally, reinstall GSX, and be sure you ALLOW all our modules to run when FSX starts again after the installation.
And no, reinstalling FSX wouldn't have fixed this, especially if you un-trusted us in the Internet options settings.