As a sidenote I found a fix to this issue by changing the permissions setting of the udev device node in /etc/udev/55-hpmud.rules from MODE=0660 to MODE=0666 . Although adding yourself to the lp and scanner groups should have worked, for some reason that solution failed.
As a sidenote I found a fix to this issue by changing the permissions setting of the udev device node in /etc/udev/ 55-hpmud. rules from MODE=0660 to MODE=0666 . Although adding yourself to the lp and scanner groups should have worked, for some reason that solution failed.