Disklavier

Can some one help me with this problem. I just received the 3.0 update 
for my mk4 and so I was going to make a backup to a hard drive for the 
first time. I followed instructions and hooked up a fat 32 hard drive 
to the usb port in the media center and when I got to the menu that 
says back up song files, I hit that and an error message comes up and 
says "file handle process is running" and it will not do a back up. Any 
ideas and thanks

Terry