Omnis Duo 'Please wait' blank screen appearing

I was wondering if anyone has come across this while DJing.

I have had two occasions when the tracks have disappeared from the screen for both my USB and SD cards. I have also been linked to Rekordbox on my PC. It has worked fine and has tended to happen near the end of an evening. I had to stop and re-boot which is really not good at all.

Has anyone a similar experience/solution?

Thank you