Depends on what Disklavier you use! Some earlier models aren´t capable of
reading/recording the 2HD disks (1,44 Mb). Try to use 2DD disks or if you can´t
get some (actually they have become rare on the market) stick a tape over the
hole without the locker on your 2HD disk and format it on your PC or Disklavier
to 720 kb and try again!
Greets
Malte