My rekordbox doesn't read my USB anymore

Hi guys,

My rekordbox doesn't seem to be able to read any devices I'm putting into my computer. It started a few days ago when i tried to put my friend's USB to play with it and now, im trying to put new music into my USB 3.0 (Which is already connected with my rekordbox) and again,not finding it in the device menu - same for the synch manager. 

It is in FAT32 and when i changed it to extFAT, he reads it but tell me that it doesn't support it.

I have a gig tomorow and i'm lost.

Thank you