That's not really an error, is just saying that, that combination of ALL of these:
- The jetway model used
- The parking as defined in the scenery (and as possibly customized in GSX)
- The exact location your airplane has been parked
- The airplane doors configurations
Result in a jetway that cannot physically reach any of the airplane doors. The most common issue is with a 737, which only has a single passenger door in front of the airplane, parking a bit too far, on a parking that has a jetway too long. The same place might work on the 2nd door of a larger plane, for example.
That's why GSX has so many jetways to choose from, and a way to TEST if they work while in the editor, simply because, as in real life, it's not possible to have a single jetway that can be used with all airplanes, so each parking usually have different kinds.
