CUPS basic auth error through web interface

Solution 1:

It's usually asking for the CUPS server's root user/pass.

Please show us your cupsd.conf configuration file.

Solution 2:

I think I figured out a solution to our problem. In the section:

# All administration operations require an administrator to authenticate...
  <Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default CUPS-Get-Devices>
AuthType Default
Require user @SYSTEM
Order deny,allow

change the "AuthType Default" to "AuthType None", you might also want to apply this change to all the other sections that involve configuring printers and managing jobs.

Hope this helps :)