CDJ 2000 NXS USB compatibility

I recently tried to load my USB (Sandisk Extreme Pro) to a CDJ 2000 NXS. I got the message on the screen labeled FORMAT. For context, my USB is formatted to MS-DOS (FAT 32) and works perfectly fine on XDJ-AZ. What can I do to remedy this? I currently use Rekordbox 6-7 to transfer my library to my USB. I also do not believe this is a firmware issue with deck because I've seen other USB types work on this unit.