XDJ-RR USB not recognized

What are the make / model / capacity of USB drives you're using, and how are they formatted (FAT32, HFS+)?

Hi. 

My USB Sticks are EMTEC 32Gb

and basically I tried every available kind of format  : MacOS Extended (Journaled), AFPS, FAT, ExFAT.... 

Sorry, but the first link (non-advertisement) that came up when I Googled that brand (which I've never heard of) was for Staples.

Any USB drive whose own manufacturer site doesn't appear at the top of the results, is not a reputable brand. I would expect the problems you're having are due to the low quality and reliability of the chipsets more than anything else.

Please try another, higher quality, drive with your XDJ-RR. Although there are literally thousands of drives on the market, only a handful of them are what I would consider good enough for use for DJ purposes. I personally will only recommend the Corsair GTX and SanDisk Extreme Pro USB3 for USB flash drives, and the Samsung T5 SSD drives for something a bit larger.

Ok thanx for your advice. I will buy SanDisk flash drive + Samsung T5 and see if it solves the problem. 

Regards.