I am having the same problem on Ubuntu 18.04. It was working on both 16 and 18 until recently.
root@T550:~# systemctl status saned.socket ● saned.socket - saned incoming socket Loaded: loaded (/lib/systemd/system/saned.socket; enabled; vendor preset: ena Active: active (listening) since Fri 2019-07-05 00:03:10 BST; 1min 46s ago Listen: 0.0.0.0:6566 (Stream) Accepted: 0; Connected: 0 Tasks: 0 (limit: 4915) CGroup: /system.slice/saned.socket Jul 05 00:03:10 T550 systemd[1]: Listening on saned incoming socket. root@T550:~# systemctl start saned Failed to start saned.service: Unit saned.service is masked. root@T550:~# service saned start Failed to start saned.service: Unit saned.service is masked. root@T550:~# -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1577137 Title: saned.service masked and cannot be unmasked To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/sane-backends/+bug/1577137/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs