[cups] intermittent cups

[Steve Root]

> 192.168.71.13 - -
> [02/Nov/2019:11:30:27 -0400] "POST /printers/MFC-J6920DW HTTP/1.1" 200
> 86493 Print-Job client-error-not-authorized.
>
> cups 2.2.10 on the rpi4. How do I fix this error?

I'm just putting together a new cups printer server and had this.
Issue was printer not shared to network and only had access by users on
cups server itself
>From my notes:

7. etc/cups/cupsd.conf

<Location />
     Order allow,deny
     Allow all  # I had to add Allow all, to access the web admin over the
network
</Location>

8. Restart cups with: systemctl restart cups.service

9. Go to web interface in browser, http://<ip>:631
Check box "share printers connected to this system"
 + check allow printing from the internet
Nb: it will redirect you to https pages then ask for your username/password
as per the account you added to the lpadmin group.

Later note: CUPS auto installed some network shared printers, but I had to
share those too (modify printer > accept all existing values but check box
to share).

HTH
Steve