E-8306: No file error on XDJ-RX

Hi
I experienced the above problem when trying to load tracks all of a sudden about 3 hours into a set. This happened with any track I tried to load on the Deck 1 or Deck 2 (the error message - E8306 No file error - showed on both decks on the screen). The only fix was to quit the rekordbox software and relaunch it and relink the laptop to the controller. However the problem occurred again soon after with any track i tried to load. Again I had to quit the software and reconnect. It may help to know an iPhone was also connected on the line in of one deck using a single jack to twin phono lead.

My Mac is running OS10.9.5 with Rekordbox 3.3 and the XDJ RX has the 1.6 firmware. I'm connecting via LINK using an ethernet cable.

Please advise.

thanks
Mark