Cannot add new printers in CUPS, showing forbidden message

[huidbui25]

I have searched the existing open and closed issues

Required Information

• DietPi version: 9.12.1
• Distro version: bookworm 0
• Kernel version: Linux DietPi 6.12.20+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.20-1+rpt1~bpo12+1 (2025-03-19) aarch64 GNU/Linux
• Architecture: arm64

Additional Information (if applicable)

• Software title: CUPS

Steps to reproduce

1. I installed CUPS using dietpi-software
2. Clicking the add printer button in CUPS brings up a password box. I realised I forgot the dietpi user’s password, but I have root access to the shell.
3. I used the shell to reset the dietpi user password with: chpasswd <<< ‘dietpi:mynewpassword’

Actual behaviour

• Now I can access the “add new printer” menu of CUPS, but there it says “Adding Printer: Error. Forbidden”

How can solve that forbidden message? What is wrong?

[huidbui25]

I found it. CUPS only works with user ‘root’, not ‘dietpi’.

[Joulinar]

Sorry to say but RTFM Printing Software Options - DietPi.com Docs