Made a backup in 4.01, then updated to 4.0.2, played a little bit, changed some performances, wanted to make a backup in 4.0.2, Kemper made the backup and then froze.
No reaction of any button pressing or turning switches.
Switched off electricity, started Kemper new, now it works again.
Tried to do a backup in 4.0.2 again. Kemper froze again. Following error message on the display this time: