firmware update problem with megadrum ARM 56

Hi Dmitri
With MDM i tried to update the firmware but the procedure does not start and always shows the same error "impossible to upgrade firmware"!
The megadrum card works normaly.
What I'm wrong?
With MDM i tried to update the firmware but the procedure does not start and always shows the same error "impossible to upgrade firmware"!
The megadrum card works normaly.
What I'm wrong?