If the position is indeed isolated in the bgl GSX won´t open since it can´t provide services for that position.
Like i said before you should contact the developer and ask them to fix the file.
Nothing GSX can do about bgl files with broken positions
to tell the truth, the scenery of EDLW 1.40 from Arima is a nice mess, the terrain after the exit is wavy like in LEAL / still not fixed even in the last update / the positions are isolated and therefore GSX does not work, so wasted money and Dortmund is on the sidelines for now. It cannot be used in such bumpy terrain.
I don't understand how someone can publish such scenery and still ask for money for it. It's completely unfinished, it's not the first or the last from Arima. My opinion.