When I used GSX in trial mode it worked perfectly but now, after buying the licence, this problem occurs.
It's not possible you would see any difference between purchased or trial, *especially* at Flightbeam KSFO, since that one is one of the airports that works in full even in Trial mode. And, nobody has reported this problem with KSFO.
Be sure you use the most updated GSX. If you are not sure, download it again.
If still doesn't work, you can also enable logging in the Troubleshooting section of the GSX Settings, and check the Couatl.LOG and Couatl.ERR that will be created.
In addition to this, I would like to know if there is any intention to make GSX deal with the jetways; I'm not able to move them either in sceneries like Aerosoft's ones nor in the defaul ones...any suggestion?
Having a product such as GSX moving jetways, instead of the scenery developer, made some sense in FS9, because in FS9 it was really hard to have moving jetways. But in FSX, since moving jetways are officially supported by the sim, and all default sceneries support them, you would guess that developers advertising a scenery made for FSX would *at least* include all features of an FSX default scenery.
We'll probably extend GSX to have moving jetways on its own in a future version, to improve the default method and get additional features too, but we plan to do it for our sceneries only, we don't have any plans to enhance 3rd party sceneries with fake/static jetways, because that would mean charging per-airport, and that's a business model we are not interested to follow.