I have lost all aircraft on my airnav screen !

I have tried most things to get them to show, all I get is the map and my home location, I have got the correct lights on the box but no flights.

I do have the Airnav handbook which I bought and have done what it says in there, but so far all to no avail.

Anyone any ideas please ?

Thank goodness flight radar24 is there, at least I can check on my Asian flights inbound.

Bill.