I experienced the same problem upon loading this spectacular airport add-on. I made sure that 1) no other KMEM AFCAD was loading (i.e. BluePrint), 2) since I have MyTraffic 6 installed, I disabled its own KMEM AFCAD (the file to disable is BR2_KMEM.BGL and is located in \MyTraffic Professional\MyTraffic\Scenery), and 3) what devgrp said...disable it in ORBX Vector, if installed (in my case, I had already disabled it but still had the problem until disabling the MyTraffic AFCAD).
All's good now and it looks fantastic.