It seems the problem doesn't have anything to do with GSX. I've just got a message from Jeffrey Stähli (SODE's author) that he's missing the Simconnect menu in ANY application ( both SODE and GSX ). The Simconnect communication works correctly, he can see both GSX and SODE calling Simconnect to create the menus, and no errors are reported on the diagnostic log. It's just the menu is not there.
The issue is, P3D 3.2 has changed the Simconnect menu for 3rd party apps to look more like the ATC menu, with transparency, and it now uses the new Scaleform library, which is based on Flash technology.
So, the real issue, as it seems, that for some reason, Scaleform doesn't work on your machines, maybe related to some problem with your P3D installation.
To verify this, you should try another 3rd party app with a Simconnect menu, like SODE. If you don't see the SODE menu either, this seems to confirm you have a problem with the new Scaleform Simconnect menu, which is entirely UNRELATED TO GSX.
Of course, I can see the Simconnect menus working normally here (both GSX AND SODE), and everybody at FSDT can see it too...
I'm afraid, if this is the case, your only chance is to file a support request to LM, because this is totally outside our control. The Addon Manager .DLL, which is the only thing that has changed, to support P3D 3.2, does NOT use the Simconnect menu.
