maybe you changed your /etc/modprobe.d/ or /etc/modules things in the past? try to be sure that you dont load anything manually.
also please confirm that /dev/ttyACM0 actually exists.
maybe you changed your /etc/modprobe.d/ or /etc/modules things in the past? try to be sure that you dont load anything manually.
also please confirm that /dev/ttyACM0 actually exists.