I installed a fresh Kubuntu-20.04, and created the first user(jacky) by means of the installer of Kubuntu, then I created the second user(leon), by using cmd-line tool "adduser", and adding it into the group "root" and "libvirt".

Both of these two users can login KDE and do things normally, but only jacky can setup printers of the system. When I login with leon and open "System Setting -> Printers", and click the button "Click here to add a new printer", I always get a error msg:

Failed to get a list of devices: 'Forbidden'

in a poped-up dialog box "Add a New Printer". If with the user jacky do so, no error occurs.

I guess these two users are different, but I don't know what difference is there and how fix it. Any hints?

Please Forgive my English!!!


Try adding your user "leon" to group "lpadmin" and log out and re-login again. I can't test this at the moment.

I'm getting the same error in openSUSE 15.2 KDE for my only user. In the journalD log, I see kde-add-printer libkcups: CUPS-Get-Devices last error: 1025 Forbidden. I'm guessing it's the same for you?

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  • Yes! You got it! But the exact group name is "lpadmin" instead of "lp". Thank you for your help! – Leon Sep 25 at 5:31

I'm assuming that you want the new user to have the ability to invoke root permissions with sudo.

Don't add the user to the root group. Add it to sudoers.

The correct command to add a user to "sudoers" is: sudo adduser <username> sudo.

You need to run this command as root, or from another user that has sudo privileges.

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  • Thanks for your help! I added the second user(leon) into the group "sudo", but it don't work. – Leon Sep 19 at 12:13

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