XDJ-700 brand new, usb stick not loading

HI. Just bought a set of 2 xdj-700 brand new. Connected to my mixer. But unfortunately usb stick that I've been using in several pioneer dj sets like 3000, a few dj controllers at the music shop in amsterdam, not being recognized by the xdj-700. Bought a new one, kingstone (my old one was from aliexpress but yet worked in all decks mentioned above) but now even the new one after being formatted to ex-fat ( I still dont know wether I should choose kilobites option as well under the format bar!!) not being recognized. 

Somebody said if I'm using recordbox, but that's not my goal. I just want to load and play. I'm beginner for goodness sake. 

So if anyone has tips please let me know. I'd be more than glad to get it work. Cheers