LSZS - a couple of things to check:
1. When you select an aircraft, you must click on it in the MyFLights aircraft list, NOT on the map.
2. What version of Radarbox are you running - the latest?
3. Can you check that your Radarbox installation is outputting data on port 30003. Open a command prompt, and type "telnet localhost 30003". Do you see lot's of lines of data?
4. Are you running any other addons that use port 30003?
Otherwise, try closing FDLite, restart Radarbox, and then restart FDLite.