Even if you haven't installed any AFCAD, you might still get a conflict, if you have products like My Traffic. And, just to be sure, have you checked a gate that is supposed to have a docking system to begin with ?
KDFW has the AGN docking system, which is NOT electronic, it's a static panel that works using an optical parallax effect, they are on terminal B and E, try terminal A, C or D, which has the more advanced system.