Bug 510067

Summary: Plasma KDE apps no longer honoring any paper setting
Product: [I don't know] kde Reporter: Stuart K. Smith <stuartksmith>
Component: generalAssignee: Unassigned bugs <unassigned-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: kdedev
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
URL: https://bugreports.qt.io/browse/QTBUG-93834
See Also: https://bugs.kde.org/show_bug.cgi?id=498566
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Requested screenshot of Region settings, KDEneon

Description Stuart K. Smith 2025-09-29 18:45:44 UTC
SUMMARY
For about 6 months now every time I use a KDE app to print (Gwenview, Kate, etc.) the paper size is set at "Photo 3.5x5". "Letter" has been my default setting forever. I have searched hours and hours through every file folder I can think of the find where this might have gotten set or changed but to no avail.

Recently I noticed something new - if I opened the print dialog, select "Letter", then close it without printing, when I re-open the dialog the paper size is blank rather than Photo 3.5x5. I also noticed that Photo 3.5x5 is the first size in the list. I believe the paper size setting is simply not being honored by KDE and Photo 3.5x5 is simply at the top of the list. This would explain why I can't find it as a setting anywhere.

Note that in non-KDE apps like LibreOffice, the paper size is defaulted to the system paper size setting which is "Letter".

Also note I have witnessed the exact same behavior in my KDEneon install (current and updated) and in freshly made KDEneon and Kubuntu 25.04 VM installs. All on KDE Plasma version 6.4.5

STEPS TO REPRODUCE
1. Open text file with Kate (or image file with Gwenview)
2. Select "Print" 
3. In the printer dialog select "Properties"

OBSERVED RESULT
Paper size is set to "Photo 3.5x5"

EXPECTED RESULT
Paper size should be set to system or locale default. In my case "Letter"


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: KDEneon User Edition/Kubuntu 25.04 
KDE Plasma Version: 6.4.5/6.4.5
KDE Frameworks Version: 6.18.0/6.14.0
Qt Version: 6.9.2/6.8.3

ADDITIONAL INFORMATION
I believe "Photo 3.5x5" appears because it is first in the list of available paper sizes in the dialog, The system default size is simply not used by KDE Plasma.
Comment 1 TraceyC 2025-09-29 22:24:15 UTC
I'm not able to reproduce this with Plasma 6.4.5 or built from git-master on Solus
Oddly, with updated VMs running Neon User or Kubuntu 25.04, I don't see the size defaulting to Photo 3.5x5, but I do see it defaulting to A4, even after setting it to US Letter in Region & Language and rebooting.

The different print menu for Libre Office Writer shows "Generic Printer", with the correct paper size of letter 8.5x11

Related - when I change Numbers, and Paper Size in Region & Language on Neon, I get an error
"Not all missing packages managed to resolve! hypen-en;language-pack-en;libreoffice-help-en-us;mythes-en-us"

I suspect this is a packaging issue with Ubuntu (That both Kubuntu and Neon are based on).
I have a couple of questions, to try to narrow down the root cause
- Can you send a screenshot of Settings ->  Region & Language on one of the systems with the bug?
- In Region & Language, if you change the paper size to something different, then back to Letter, do you see an error?
- On the VM, what printer is shown for KDE apps? I only have "Print to File (PDF)" in my VMs.
Comment 2 TraceyC 2025-09-29 22:34:28 UTC
I did a little more digging and found bug 498566

It appears this is an issue with the Qt print dialog, and there's a bug to fix this in the Qt toolkit
https://bugreports.qt.io/browse/QTBUG-93834
Comment 3 Stuart K. Smith 2025-09-30 12:41:29 UTC
Created attachment 185396 [details]
Requested screenshot of Region settings, KDEneon
Comment 4 Stuart K. Smith 2025-09-30 12:44:28 UTC
(In reply to TraceyC from comment #1)
> - Can you send a screenshot of Settings ->  Region & Language on one of the
> systems with the bug?
Attached

> - In Region & Language, if you change the paper size to something different,
> then back to Letter, do you see an error?
Yes: First , a message flashes too quickly to read, then I see "Failed to install package Failed to obtain authentication." However oddly, the change is saved.

> - On the VM, what printer is shown for KDE apps? I only have "Print to File
> (PDF)" in my VMs.
I installed my networked printer to the VMs.
Comment 5 Stuart K. Smith 2025-09-30 12:47:48 UTC
I tried a second time to change paper so I could read the first error. Instead I got these three lines:

Changes will take effect the next time you log in... [Restart Now]
Failed to install package Failed to obtain authentication.
Necessary locale and language support files have been installed. It is no safe to turn off the computer.
Comment 6 TraceyC 2025-09-30 15:09:04 UTC
(In reply to Stuart K. Smith from comment #5)
> I tried a second time to change paper so I could read the first error.
> Instead I got these three lines:
> 
> Changes will take effect the next time you log in... [Restart Now]
> Failed to install package Failed to obtain authentication.
> Necessary locale and language support files have been installed. It is no
> safe to turn off the computer.

That error sounds like a packaging / configuration issue with with KDE Neon. I'd suggest opening a separate bug report for that, and we can send it to the Neon folks
Comment 7 Stuart K. Smith 2025-09-30 16:06:29 UTC
(In reply to TraceyC from comment #6)
> (In reply to Stuart K. Smith from comment #5)
> > I tried a second time to change paper so I could read the first error.
> > Instead I got these three lines:
> > 
> > Changes will take effect the next time you log in... [Restart Now]
> > Failed to install package Failed to obtain authentication.
> > Necessary locale and language support files have been installed. It is no
> > safe to turn off the computer.
> 
> That error sounds like a packaging / configuration issue with with KDE Neon.
> I'd suggest opening a separate bug report for that, and we can send it to
> the Neon folks

If it's Neon only why do I see that exact same behavior in Kubuntu?
Comment 8 TraceyC 2025-10-01 14:35:17 UTC
It may be an issue with the Ubuntu sources they both use. In any case, if you open a new bug report for the error the Neon folks can look into it.