Using XDJ Aero as a controller - setting to mixer mode

I was having a great deal of trouble getting Rekordbox DJ, or Virtual DJ, or Flow 8 Deck, to recognize my XDJ Aero. At best one or two controls would work, and I tried all manners of restarts. 

Finally I figured out that on the Aero unit itself I had to:

- long press Utility

- scroll down to Mixer Mode

- set to PC

Now it works!