Disklavier

Hi everyone. 
I am a newbie to this site and downloaded some midi files from here.  
Unfortunately when I put them in my disklavier it gives me the 
message "disc not formatted".  I had formatted them on the computer and 
then did the download to the disc.

Is there some procedure problem I am missing here??

Thanks for any advice or help.

Oh, the unit is a MX-100 on the U-1. It is a used unit from early 
2000's.
Thanks,
Rob G.