Hello Spiro, sorry. It's my fault. After uninstall and 'install install-plugin-xum1541' everything works as expected. My be my old installation leave some old parts .. Please close the ticket. Thank you for the fine work ;-). Now i can take a look on my old c64 floppy disks (about 100 old games and more ;-)).
modprobe -v cbm -> insmod /lib/modules/4.9.0-5-amd64/misc/cbm.ko -> modprobe: ERROR: could not insert 'cbm': No such device