Tried first the following:
Hardware > Printers says
Printer service not available. Start the service...
However, Start Service - button is greyed, only Connect - button usable, "Not connected" on lower left corner of dialog.
Tried then Connect > Connect to CUPS server (localhost)
CUPS server error, failed to connect to server
Checked via Terminal, if cups processes are there :
$ ps -ef|grep cups root 796 1 0 08:36 ? 00:00:01 /usr/sbin/cups-browsed root 2673 1 0 09:09 ? 00:00:00 /usr/sbin/cupsd -l lp 2679 2673 0 09:09 ? 00:00:00 /usr/lib/cups/notifier/dbus dbus://
Then tried HPLIP Toolbox:
HP Device manager says
No Installed HP devices found
Used Setup device - button, did Manual Discovery > Next, and printer was discovered. Clicked Next, on textbox
PPD File Not found, click browse...
Browsed and found Downloads/ppd/hpcups/hp-envy_4500_series.ppd, used it and clicked Add printer
Printer queue setup failed, Error: unable to connect to CUPS server
Any ideas, please ?
Additional details :
The problem occurs after each boot. If I then kill the cupsd and start it again with sudo and with same parameters = sudo /usr/sbin/cupsd -l & , printer will be visible again, but only to next boot, below is what I actually do to get this temporary solution:
xxxxx@D830:~$ ps -ef|grep cupsd root 700 1 0 15:30 ? 00:00:00 /usr/sbin/cupsd -l xxxxx 2432 2311 0 15:33 pts/0 00:00:00 grep --color=auto cupsd xxxxx@D830:~$ sudo kill 700 [sudo] password for xxxxx: xxxxx@D830:~$ sudo /usr/sbin/cupsd -l &  2442 xxxxx@D830:~$ ps -ef|grep cupsd root 2442 2311 0 15:34 pts/0 00:00:00 sudo /usr/sbin/cupsd -l root 2443 2442 0 15:34 pts/0 00:00:00 /usr/sbin/cupsd -l xxxxx 2446 2311 0 15:34 pts/0 00:00:00 grep --color=auto cupsd
For A.B. Open a browser and use this URL: localhost:631. What happens?
- "Firefox can't establish a connection to the server at localhost:631"
For A.B. Post the output of this command in your question:
grep cups /var/log/syslog* Apr 29 15:30:08 D830 ureadahead: ureadahead:/var/spool/cups/tmp/cups-dbus-notifier-lockfile: No such file or directory
(This is the only row in syslog after boot)