Can't print via CUPS

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#1

Suddenly my Samsung printer fails to print with the following error in the CUPS log…

W [18/Aug/2023:15:34:40 +0200] CreateDevice failed: org.freedesktop.DBus.Error.ServiceUnknown:The name org.freedesktop.ColorManager was not provided by any .service files
W [18/Aug/2023:15:34:41 +0200] CreateProfile failed: org.freedesktop.DBus.Error.ServiceUnknown:The name org.freedesktop.ColorManager was not provided by any .service files
W [18/Aug/2023:15:34:41 +0200] CreateDevice failed: org.freedesktop.DBus.Error.ServiceUnknown:The name org.freedesktop.ColorManager was not provided by any .service files
W [18/Aug/2023:15:35:21 +0200] [Job 10] Grayscale/monochrome printing requested for this job but Poppler is not able to convert to grayscale/monochrome PostScript.
W [18/Aug/2023:15:35:21 +0200] [Job 10] Use "pdftops-renderer" option (see cups-filters README file) to use Ghostscript or MuPDF for the PDF → PostScript conversion.

It was working fine before my last “dup”. I don’t understand how I can “Use "pdftops-renderer" option” and can’t locate the cups-filters README file. The printer was setup with YaST and I have tried both drivers offered to print a test page. It’s a great printer and I am not about to change it.

Any suggestions will be appreciated.

#2

the W are warnings - not errors.

What is in /var/log/cups/error_log with dates since the last “dup”

if the log is large you can clear it with the below code and see what cups is finding:

sudo   >   /var/log/cups/error_log
sudo systemctl restart cups
sudo systemctl status cups                                (q to get out of the display)
cat /var/log/cups/error_log

You can just cut and paste the 4 lines above in a terminal - It should say why.

#3

Thanks for the speedy response. My results.

ion@Box2:~> sudo   >   /var/log/cups/error_log
bash: /var/log/cups/error_log: Permission denied

ion@Box2:~> sudo systemctl restart cups
[sudo] password for root: 

ion@Box2:~> sudo systemctl status cups
● cups.service - CUPS Scheduler
     Loaded: loaded (/usr/lib/systemd/system/cups.service; enabled; preset: enabled)
     Active: active (running) since Fri 2023-08-18 17:55:25 CEST; 16s ago
TriggeredBy: ● cups.socket
             ● cups.path
       Docs: man:cupsd(8)
   Main PID: 4414 (cupsd)
     Status: "Scheduler is running..."
      Tasks: 1
        CPU: 134ms
     CGroup: /system.slice/cups.service
             └─4414 /usr/sbin/cupsd -l

Aug 18 17:55:25 Box2 systemd[1]: Starting CUPS Scheduler...
Aug 18 17:55:25 Box2 systemd[1]: Started CUPS Scheduler.
ion@Box2:~>

cat /var/log/cups/error_log produced a large file of repeated warnings as in my first post.

#4

I’m now pretty sure it’s a hardware problem and will try to find some specific diagnostic software from Samsung. Thanks for the help.

#5

Ok the error log file did not get cleared so we remove it - it gets recreated if missing on a start of cups

sudo systemctl stop cups

sudo rm /var/log/cups/error_log

sudo systemctl start cups
#6

My laser printer also showed those warning but prints fine.

org.freedesktop.ColorManager was not provided by any .service files seems to be a common warning for many printers.

no idea on how to get rid of it

#7

I was wrong about it being a hardware problem as it works under Windows 10. I tried one more time after I had deleted the printer and was trying to re-configure using YaST. It now reports “Cannot access cupsd on ‘localhost’” and can’t start the CUPS daemon.

Box2:/home/ion # lpstat -h localhost -r
scheduler is not running
Box2:/home/ion #

So how do I start the scheduler?

#8

Is the port 631 blocked?

in a browser (firefox or chromium) 127.0.0.1:631

should bring up :

CUPS 2.2.7

CUPS is the standards-based, open source printing system developed by Apple Inc. for macOS® and other UNIX®-like operating systems.

If not port 631 is blocked on the computer.

#9

No success. No firewall running.

Unable to connect

Firefox can’t establish a connection to the server at 127.0.0.1:631.

    The site could be temporarily unavailable or too busy. Try again in a few moments.
    If you are unable to load any pages, check your computer’s network connection.
    If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the web.
#10

Or there is no daemon listening. Which concurs with his scheduler is not running.

#11

I assume you must try to concentrate on this “suddenly”. It may appear to you as “suddenly”, but most of the cases something was done, like update. change hardware, whatever.

#12

I think you are right. Instead of “suddenly” it should have been “unexpectedly”.

#13

But the same logic applies. What changed between the last time “it worked” and the first time it didn’t. I know that is not always obvious, but nevertheless it could be important.

#14

If cups is running and not blocked then 127.0.0.1:631 should bring up the cups menu.

port 631 is blocked or cups is not running.

When all else fails you can try removing cups and reinstalling it. remove /etc/cups while it is removed - I just rename it to /etc/cups.bad

Is the printer attached to Windows or OpenSUSE

#15

When I use a browser I can connect to http://localhost:631/admin/ but when I try to add a printer it tells me `

Add Printer
Add Printer Error

Unable to add printer:

Forbidden

`

#16

Earlier in the thread you reported cupsd was active when you ran sudo systemctl status cups. The service uses socket and path based activation, so may only be active when triggered first.

Let’s see the results of the following command:

sudo systemctl status cups.{service,socket,path}
#17

Are you using your root credentials?

#18

Box2:/home/ion # sudo systemctl status cups.{service,socket,path}
● cups.service - CUPS Scheduler
Loaded: loaded (/usr/lib/systemd/system/cups.service; enabled; preset: enabled)
Active: active (running) since Fri 2023-08-18 22:04:50 CEST; 12min ago
TriggeredBy: ○ cups.path
● cups.socket
Docs: man:cupsd(8)
Main PID: 15905 (cupsd)
Status: “Scheduler is running…”
Tasks: 1
CPU: 1.115s
CGroup: /system.slice/cups.service
└─15905 /usr/sbin/cupsd -l

Aug 18 22:04:50 Box2 systemd[1]: Starting CUPS Scheduler…
Aug 18 22:04:50 Box2 systemd[1]: Started CUPS Scheduler.
Aug 18 22:12:20 Box2 cupsd[15905]: gkr-pam: unable to locate daemon control file
Aug 18 22:12:20 Box2 cupsd[15905]: gkr-pam: stashed password to try later in open session

● cups.socket - CUPS Scheduler
Loaded: loaded (/usr/lib/systemd/system/cups.socket; enabled; preset: enabled)
Active: active (running) since Fri 2023-08-18 22:04:50 CEST; 12min ago
Triggers: ● cups.service
Listen: /run/cups/cups.sock (Stream)
CGroup: /system.slice/cups.socket

Aug 18 22:04:50 Box2 systemd[1]: Listening on CUPS Scheduler.

○ cups.path - CUPS Scheduler
Loaded: loaded (/usr/lib/systemd/system/cups.path; enabled; preset: enabled)
Active: inactive (dead) since Fri 2023-08-18 20:57:44 CEST; 1h 19min ago
Duration: 30.348s
Triggers: ● cups.service

Aug 18 20:57:13 Box2 systemd[1]: Started CUPS Scheduler.
Aug 18 20:57:44 Box2 systemd[1]: cups.path: Deactivated successfully.
Aug 18 20:57:44 Box2 systemd[1]: Stopped CUPS Scheduler.
Box2:/home/ion #

#19

You mean run Firefox as root and do it? I thought that was not advisable.

#20

No, I mean when undertaking administrative tasks with CUPS you should be prompted by a popup requesting root credentials.,