Basically, a corruption of the CUPS policy file stops CUPS from running until the corruption is removed.
My printing stopped working after a late November 2025 update. Basically, only Airprint drivers would appear in a print dialog, and those drivers could not connect to anything when selected (and so there was no printing at all).
I tracked the error down to CUPS not operating
$ sudo service cups status
[sudo] password for victor:
○ cups.service – CUPS Scheduler
Loaded:
Continue Reading CUPS configuration error and fix
