GSX correctly reported that, since the jetway hasn't connected properly, passengers won't be seen. In previous version, this would result in passengers in the air, leading user assuming there was a problem in GSX, when the only problem is the jetway is not connecting.
GSX doesn't have any control if the jetway connects or not, it doesn't control jetways, it doesn't for its own jetways ( to be used only on default airports ), let alone for jetways from other developers.
The things that affects whether a jetway would connect or not are:
- How the jetway is modeled and what how it can physically extend and reach.
- The relationship between the jetway placement, the airplane door AND the way you parked.
The last thing ( the way you parked ) might have SOME indirect relationship with GSX, depending if the scenery offered its own parking system or you are using one that might have been eventually added by the GSX profile you downloaded.
If you followed the parking system included with the airport, it's not granted that this would result the jetway always working at all position. Nothing we control, nothing we can possibly know, because it depends entirely by the scenery and its parking system.
Instead, assuming the airport profile you are using comes with GSX replacement parking systems, and assuming you are following them correctly, it's *possible* whoever made that profile might have not tested the jetway at that particular position, so it MIGHT be possible to fix this by editing the Stop position.
GSX has a "Test" feature that allows to verify if a jetway works from a certain position.
It might be even possible that, with a certain airplane model, that particular jetway might never work, no matter how you are parking. Again, nothing we can do about it from GSX.
The only thing GSX can do, is WARN you about the jetway not having connected properly, so you know why passengers are not there.
Now, last possible case is, the message is not right, because as far as you can tell, the jetway connected perfectly.
If THIS is the case, the most likely cause is you haven't Disabled the GSX Jetway replacement files for that airport, something you are always supposed to do when installing a new scenery after GSX, the GSX Manual has all the details about this at Page 7, no need to repeat it here.