Hey Guys, question, at certain airports, KIAH and CYYZ, once the simulator is loaded and traffic nav lights come on ready to push off the gates, the traffic sits there and does not push back or take off....I just did a flight into CYYZ and traffic was coming in fine and taxiing to their respective gates, however, I noticed a plane there that had its nav lights on ready for pushback, I look back and it has disapeared....Same thing happens at KIAH, I go there and see a bunch of traffic ready to push back and they sit there, and then they disapear...anyone know whats going on? AFCAD issue?

Often it is an AFCAD issue, rarely a traffic problem.If there isn't a valid route from the parking spot to the black runway taxi line (in AFCAD) of the assigned runway, then the plane will disappear instead of taxiing. Common reasons are usually caught by the Fault Finder (like broken taxiways), but sometimes it's a missing black runway line, ATC using what you think is a "closed" runway, or other error.The traffic problem can occur either if the destination airport is within 108 NM and is full, or the plane is late and should already be departing from the next airport in its flight plan.There may be other things that can do it too - I've also seen them disappear for no apparent reason...Hope this helps,