Ubuntu 17.10 / 18.04 has been giving popup messages about auto-adding “new” printers each time I connect to a wired or WiFi network.
Stop the auto-add printer on network connect by:
- restart CUPS from Terminal:
service cups restart
Reboot PC with network disconnected, check that the offending printers are not in Settings → Printers, and then connect to the network and verify that the printers don’t auto-add again.