xdj rx stops

i have some problems in my laptop  . rekordbox sometimes stops working suddenly and it gives me that the rekordbox is not responding.. therefore i used to put a usb in the xdj rx as backup in case rekordbox has stopped . yesterday when i was playing on my set . rekordbox has stopped suddenly . But infortunetly i wasn't able to use the usb instead . The 2 usb has stopped also on the rx So i was forced to stop the music... what would be the issue ??