I've had this problem for over 2 years, but Airnav have shown no interest in trying to help me with it
I've not contacted Airnav as suggested in the previous posting as I guessed that the response would be similar to your experience.
When I first received my box and installed the software, as a professional programmer now retired, I was rather surprised at the poor quality of the program. My 'professional' report to them was a waste of my time.
I guess that it's time to 'cut my losses' and go elsewhere.
Airnav need to 'come clean' with their customers about an update to the program and say; sorry but we will not be producing an update to an obsolete product (hardware & software), as it does not make commercial sense.
Thanks for the time taken to respond.