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Please see the official X‑Plane Support page for help.
This is more properly a question for the developer of that plugin.
I also use that plugin, and it works for me.
Please, it is crucial that you follow the instructions posted on the download page: http://forums.x-plane.org/index.php?/files/file/14790-ground-services-pushback-refueling/ word for word. The required libraries are required to run the Ground Services Utility. Hope you get it installed!
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