I think that when you install vc redist 2013 error occurs..
If you have a problem with VC++ 2013 libraries, GSX will not even appear under the "Addons" menu, because those libraries are required for the program to start.
Or, are you saying that, if you DON'T install the VC++ 2013 libraries, the program works (the installer automatically install them), but if you install it manually, its menus will then become inoperative ?