H.E. - this software is very useful and easy to use. I use it to develop .KML files for almost every outing with my ANAFI.
I noticed your comment above - my data is also empty re the true airspeed. I believe that all my firmware and software versions are current. Freeflight 6 shows "speed" on the graphics output; not sure if this is the same as "True Airspeed" from the .JSON file. This is not critical to me - just curious.
Great program and your efforts are very much appreciated.