That model is not supported yet. You can check an updated list of supported models here:
http://www.fsdreamteam.com/forum/index.php/topic,5481.0.htmlWhen any airplane is not internally supported by GSX, and if you don't wait to wait for us to add it, you can use the included airplane configuration utility to place all doors, which is very easy.
The tricky part it's usually figuring out the variables that controls the doors, since Captain Sim usually use custom XML variables for all their doors. To configure a door that uses a custom variable, you must use an XML expression. Page 30 of the GSX manual explain this, with an example XML expression, so you only need to replace the L:MyVar in the example with whatever name Captain Sim used for that door.
Custom XML names can be usually gathered by looking at the airplane external model .MDL file with an hex editor, searching for the "door" string, usually returns some meaningful results.
If you don't want to do any of this, just place the doors visually, and set each door in GSX to be a "Door with no Open/Close checks". This is DIFFERENT than saying "No door at this position", which will cancel all services. It tells GSX to NOT WAIT for you to open the door to start a service.
Of course, if you forget to do it, the service will start in any case, and you might see people passing through the airplane bulkheads, which is the main reason why GSX, by default, wait for a door to be opened.
