USB not loaded on XDJ-1000's

Yoo,

Frustrated as I am, I came here to ask for help. I play with xdj-1000's. They work perfectly and are quite fresh (few months). Though, this afternoon I encountered a problem which has been considerably fucking frustrating, to say the least. 

When I insert my USB, the xdj's do recognize the presence of a USB, though they do not load any of the tracks that are on it. I have used the same USB throughout the months since I got the xdj's, and did not ever have any problems. 

I do load the tracks in rekordbox and I do everything the way I should (I think?). Can somebody please tell me what to do, I just want to play my friggin' tracks...

Thanks in advance and best regards,

A reasonably frustrated dj