Geoff,
All data comes from the database whether onboard or on the server depending on myflights or network
The aircraft table this morning has 232,551 records and the routes table is showing 315,368 records. When you carry out a database update the software downloads the server database onto your computer as a Navdata.db3 file and places it in your data folder.
If you use windows search and look for NavData.db3 you will find all instances of it. There will be other Navdata.db3 files with other extensions but look only for this one. You should then be able to move the correct Navdata.db3 over and replace the old one which is being used. Don't have RB running while you do this.
The received data is a hex code and a call sign and the software matches the hex with the other aircraft details from the database and displays them on screen. The call sign gives the route and again the software matches the call sign with the route details held in the database and matches them for display. If the details are not in the d/b, no info can be shown.
Alan