Yeah, its Gayasims vienna sold By orbx. The version is like a Market place Version. This has been discussed in another topic too.
What do you mean with "is like a Market place Version", is the scenery encrypted in some way ? If yes, there's no way GSX or any other utility would be able to read it. Or, is the AFCAD non-standard, or corrupted in some way ?
It would be nice if gsx would offer some workaround to have those Airports modifed as well Even of the dev of the Airport wont Update it
GSX already has a workaround for Marketplace / encrypted airports, and is to place a DRM-free version of the airport file in the GSX profiles folder, but this requires SOME support from the original developer. If this is the problem, which I still not sure if is.
Do you have a log showing if the airport has been rejected for any reason ?