removable drive - device library corrupted

Hi,

Updating my 2 usbs last night with new tracks/playlists.  

First one updated as normal with no issues..  However the 2nd came up with the error:  

"Removable drive - device library corrupted, Do you want to delete the device library".

Is this basically an issue with the USB itself as the other usb was fine when updating?  Ive looked on similar threads and it seems I will need to re-format the old usb and export everything again.. Is this correct?  Or is there any other way around it?

Also would the size of my rekordbox collection cause any issues?

The usbs have not really been anywhere that would corrupt them so not sure how its happened.

Any advice appreciated..

Thanks

Simon