I have just installed a Dension Gateway 500 in my 05 E60 530i sport

My car had the cd changer in the glove box and a single cd slot and dvd slot just below the heater controls

Cd changer played Cds before I removed it. Once I removed the cd changer I split the power connector and the 2 fibre optic connectors that went into the back of the cd changer

Using the connectors that came with the Dension unit, I installed a new connector on the fibre optic connections making sure the input and output went in the right way.

I then connected the Dension power connector to the cd power connector. Positive to positive and negative to negative. I also ensured that the first 2 dip switches were up and the rest were down as per the Dension instruction manual

I updated the Dension using the latest firmware from the Dension website and can confirm it worked because it removed the rom file and left bin files behind

Now I insert my usb stick (which works in my pc and usb stereo in wifes car) nothing happens. I choose Cd mode on the idrive. It goes to CD5 and track 99. But I get no music. If I choose a different track like track 1 or 6 it just goes back to track 99

Is it because I need MP3 enabled on the car or is the single slot cd player causing the issue or is there another issue??

Thanks