I create my own airlines/traffic flights on FSX.
The traffic files are always saved to Scenery/World/Scenery folder.
The files are no longer there, but the aeroplanes are still flying around as if the files are still there.
Is there any other location that the 4 files (aircraft/airports/flightplans/traffic) could have been moved to? Is it possible the traffic aircraft work from another folder?
If you don't have it installed in the default location, check there eg C:\Program Files (x86)\Games\Flight Simulator