Gsx not appearing in Addons window (Fsxsteam)

[Pepe747]

I have downloaded GSX but when I open FSX it doesn't appear in the addons windows.

[virtuali]

The thread named "Addon Manager not showing up in P3Dv4 **SOLVED**" thread lists all the known solutions for any missing libraries:

http://www.fsdreamteam.com/forum/index.php/topic,17484.msg122656.html#msg122656

Even if the title says P3D4, the solutions are valid for FSX as well.