Quoting from the GSX Manual, Page 8:
There might be some cases where you might need to DISABLE the “Airport Services” for specific ICAOs, usually because a 3rd party airport already comes with them. It’s difficult to give a general suggestion when you need to disable the GSX Airport Services, and it really depends what the 3rd party airport used an Airport Service file for.
I suggest reading the rest of the chapter, which explains the cases, no point repeating it here.
But in general, you don't usually disable Airport Services, unless the scenery comes with their own, which means it has an "AirportServices" folder in its package.
