The recent cups update has fixed this issue. Adding the Canon MG-6320 with LPD/DNS-SD was successful and prints jobs correctly.
** Changed in: cups (Ubuntu) Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1810728 Title: cups error - internal server error when adding a printer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cups/+bug/1810728/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs