I added an overlay to my home airport and added some traffic. I fire up MS and sit and watch the traffic. When an aircraft arrives it taxies to the gate assigned by ATC. So far so good,now the same aircraft is scheduled to depart in say half an hour. On the dot it gets its clearance and then poof....it disappears. It happens at random at all gates and to all aircrafts. It cant be a broken taxiway line because it did taxy to the gate and moreover another aircraft did taxy from that gate foor take off when I initially started FS. There is enough space to make a 180 degree turn so its not blocked that way also and it also happens when there is not another aircraft within 500meters.Any idea guys.... I am stumpedzorro3012

When you did the overlay, did you keep ALL the taxiway lines in AFCAD for both the overlay and the original airport? What may have happened is that the arriving aircraft got sent to the "wrong" overlay by ATC, and when it tries to get to the runway in use by the "right" overlay there is no path.Arriving aircraft will be sent to the overlay whose airport location point (the pink cross in AFCAD) is closest to the point where the aircraft leaves the runway and contacts Ground. This is most noticeable when the overlays use different crossing runways, and less of a problem with parallel runways. You can use more recent versions of AFCAD to move the airport location point.To see if this is your problem, note which overlay the arriving aircraft is supposed to go to (from the Flightplans file) and then see which overlay ATC parks it on. Then note which runway ATC sends it to for takeoff, and see if there is a path to that runway.In general, when I create overlays I copy the original AFCAD file and just delete parking, leaving all the taxiways. Then I selectively open and close runways for each overlay, and finally I try to make sure that the airport location points for each overlay are the closest ones for the arriving runway for that overlay.