The “warning: CUPSEXT could not be loaded. Please check HPLIP installation” message usually indicates that there is an issue with the HPLIP (HP Linux Imaging and Printing) package installed on your Linux system. This message can occur when trying to use the HPLIP toolbox or run a HP printer setup.
To resolve this issue, you can try the following steps:
- Uninstall HPLIP:
sudo apt-get remove hplip
- Reinstall HPLIP:
sudo apt-get install hplip
- Run the HPLIP setup:
sudo hp-setup
- Restart CUPS (Common Unix Printing System):
sudo service cups restart
- Restart the system:
sudo reboot
These steps should resolve the issue and allow you to use the HPLIP toolbox and set up your HP printer without any error messages. If the issue persists, you may need to consult the HPLIP documentation or the HP support website for further assistance.