This is relevant for you:
https://discussions.flightaware.com/t/for-beginners-how-to-get-back-existing-station-number-in-a-fresh-install/30981
Otherwise you need to set the location to get MLAT running.
This is relevant for you:
https://discussions.flightaware.com/t/for-beginners-how-to-get-back-existing-station-number-in-a-fresh-install/30981
Otherwise you need to set the location to get MLAT running.