The problem is caused by your sim not finding the GSX Simobjects folder, which of course is not normal, since the installer will surely add it to its search paths. So, the problem is likely one of your simulator config files.
You use P3D 3.2 so, you might have been mislead of other posts suggesting to edit the FSX.CFG (or Prepar3d.cfg) file but, in P3D 3.2, the file used to store Simobjects paths is here:
%PROGRAMDATA%\Lockheed Marting\Prepar3d v3\simobjects.cfg
Check that file, and see if you have an entry that points to the GSX Addon Manager\Simobjects folder. It's supposed to be added by the installer.
In addition to that, I strongly suggest to update P3D to 3.4, which adds support for the add-on.xml package system, and reinstall GSX there, so it won't be affected anymore by an eventual problem of that file.