Dennis, the file /lib/udev/rules.d/56-hpmud.rules is part of the "hplip" package. Make sure the "hplip" package is installed. If it is already installed, run
sudo apt-get install --reinstall hplip
to refresh its installation.
Dennis, the file /lib/udev/ rules.d/ 56-hpmud. rules is part of the "hplip" package. Make sure the "hplip" package is installed. If it is already installed, run
sudo apt-get install --reinstall hplip
to refresh its installation.