Problems with KDE and Wayland

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1

Hello everybody.

I am facing problems with wayland.
Quite recent computer.

Operating System: Kubuntu 26.04
KDE Plasma Version: 6.6.4
KDE Frameworks Version: 6.24.0
Qt Version: 6.10.2
Kernel Version: 7.0.0-15-generic (64-bit)
Graphics Platform: Wayland
Processors: 32 × Intel® Core™ i9-14900KF
Memory: 128 Gio of RAM (125.6 Gio usable)
Graphics Processor: NVIDIA GeForce RTX 3090

Somme application were not displayed in the task bar with wayland. But recenly I messed up my configuration, some stupid apt commands. I fixed that and every thing works as before, but ligh-locker crashes. Now, the taskbar is not showing up in wayland session. But sometimes after a change it has been displayed, and on the next time i connected it dissapeared again.
I tried everything I found on the Internet, in fact not that much available.

I compared pakages installed with the ones installed on a second PC, same distribution. It is exatly the same but what must be different (GPU and hardware drivers, and some applications).

I found this in syslog, may be the explanation, may be not
2026-05-21T13:28:20.871279+02:00 pascal-fixe systemd[3131]: Stopping plasma-plasmashell.service - KDE Plasma Workspace…
2026-05-21T13:28:20.951374+02:00 pascal-fixe plasmashell[3481]: qrc:/qt/qml/plasma/applet/org/kde/plasma/notifications/global/Globals.qml:134: TypeError: Cannot read property ‘screenGeometry’ of null
2026-05-21T13:28:20.963565+02:00 pascal-fixe plasmashell[3481]: qrc:/qt/qml/plasma/applet/org/kde/plasma/notifications/global/Globals.qml:264: TypeError: Cannot read property ‘plasmoid’ of undefined
2026-05-21T13:28:21.079200+02:00 pascal-fixe systemd[3131]: Stopped plasma-plasmashell.service - KDE Plasma Workspace.

Could somebody help me please. What to search ?

2

I just add that this information does not show up with X11 session, I must use as long as the taskbar does not work with wayland.

3

The error logs you are seeing indicate that the plasmashell is crashing because the notifications applet is unable to retrieve screen geometry data, which is a known symptom of corrupted local configuration files. To resolve this, you should perform a clean reset of your Plasma desktop settings. First, ensure you have backed up any important data. Then, log out of your graphical session and switch to a TTY (Ctrl+Alt+F3). Log in and try moving your existing configuration directory to a backup location to force a clean regeneration upon your next login: run mv \~/.config/plasma-org.kde.plasma.desktop-appletsrc \~/.config/plasma-org.kde.plasma.desktop-appletsrc.bak and rm -rf ~/.cache/plasma*. Afterward, reboot your system. If the issue persists, check your ~/.config/kdeglobals file for any manual SceneGraphBackend overrides, as these can conflict with Wayland and NVIDIA drivers, and remove them if found.

4

Thank-you. I test that right now. I created a new user and the problem exists also with this new user. I let you know.

5

This isn’t an issue with your config, as it occurs also with a new USER.

Are there any errors when you run updates?

What’s in your journalctl?

journalctl -p3 -xb --no-hostname

6

After reviewing the technical logs and the latest community reports, it is now confirmed that you are encountering a known regression within the KDE Plasma 6.6 notification applet (Bug 519046). The error ‘TypeError: Cannot read property ‘screenGeometry’ of null’ occurs because the applet lacks a proper null-guard when initializing on certain display configurations, which is why creating a new user profile does not mitigate the issue. This is a software-level defect in the QML codebase, particularly affecting Wayland sessions. Since this is an upstream bug, I suggest tracking the progress on the official KDE Bugzilla report. As an immediate workaround, some users have reported success by disabling the ‘Notifications’ applet from the system tray settings or by switching to an X11 session until a patch is merged in the next point release.

7

OK, thanks. I’ll try that. But anyway the only way I found until now is to use x11 session.

Thank you for this efficient response.

8

That is a sensible workaround; switching to an X11 session effectively bypasses the compositor-level issues currently affecting the Wayland notification stack in Plasma 6.6. It is a stable way to maintain functionality while the upstream patch for Bug 519046 works its way into your distribution’s repository updates. You should be able to revert to your preferred Wayland session once your system receives the update that includes the null-guard fix for the Globals.qml component. Glad to hear you are back up and running.

9

sounds like you borked your system.

typically, unless you have a snapshot you can roll back to, this means a reinstall.

you can try a new user and see if displays the same sorts of problems… it that works as expected, then it only a matter of cleaning up your user files and the rest of the system is ok.

everything about your personalization of the install is located in either .config or .local

you can rename those folders and reboot, which will give you back all the defaults just like the new user acct and then you can slowly move the contents of the renamed folders back one chunk at a time to help narrow down which file is the problem file.

from my notes:

# brute force troubleshooting...
mv ~/.config ~/.configBORKED
mv ~/.local ~/.localBORKED
# logout and log back in again to force plasma to recreate the folders with default settings
# open split views of the folders for comparison and file copy
dolphin --split ~/.config ~/.configBORKED
dolphin --split ~/.local ~/.localBORKED
# copy back half of the BORKED folder contents at a time and relog to see if issue returns
# if it does, then delete the folder again, relog, and only copy half of that previous half
# repeat until the culprit is found, then finally, copy back everything BUT that culprit bit
10

No, it is not due to a broken configuration. A new user, with a brand-new configuration has the exact same problem. I believe the problem is identified. I cannot use Wayland until the bug pointed by MarcelStevano is corrected.

Wayland never worked on this PC, the problem was that not all applications were displayed in the task bar, what makes its use impossible. So I use Plasma X11 session. I maintain my system up to date. And I upgraded Plasma 6.6. The fact I messed up my configuration and repair is is not the cause.

I have another PC, an old one, for which Microsoft suggest me to replace by a new one, and suggest me links to buy a PC. So I installed KUbuntu. And the PC works fine for what I do with it. Bye bye, Microsoft, my pleasure not to see you again. This PC works event better with Wayland then X11. That is the aim of Wayland no suprise.

There are still some glitches as knip not working, the Wayland Icon displayed for some applications as Blender or Chitubox instead of their own. I regret that no driver is available for the NVIDIA GeForce 710M in this recent distribution. But the PC works far better than it was with Windows10.

Then as this old PC works with Wayland, I tested on the recent one thinking the problems could be solved, and noticed the problem with the taskbar, problem due to Plasma 6.6, the NVIDIA driver, may be the fact that I have a graphic tablet that is not always connected.

Obviously Wayland still have some problems to be solved (Applications not working as ksnip), this problem with Icons what make difficult to select the application in the taskbar. I hope developpers will stablize and correct this.

But I beleive this is the right track for Linux to become a mature system, widely adopted.

For the time being, Linux is already the solution to save millions of the old PCs over the world which users have been betrayed by Microsoft, to make more money, whatever the consequence on pollution and climate charge.

Sorry it may not be the place to tell my hanger against Microsoft, and tell how gratefull I am this solution could save this old PC, gratefull also to all developpers and communities to bluild this solution.

11

Ok, but this ‘bug’ doesn’t exist on my KDE Plasma system…

However, you did include Cannot read property 'plasmoid' of undefined which seems to imply that you have added a dodgy plasmoid…

However, that shouldn’t exist on a new USER.

You should include system details - I suspect this might be one of those nVidia features which crops up oh-so-frequently…

NVIDIA GeForce 710M

Ah, remove that - everything should improve :wink:

So maybe edit the thread title to read:

‘Problems with nVidia GeForce 710M with KDE and Wayland’.

The issue isn’t actually with KDE and Wayland.

12

The last post confused you. Read it and you will understand. I thank everybody acting to develop Linux, Kde, and other applications and helping people.

I never said that the absence of drivers for the NVidia GeForce 710M is a matter of KDE or wayland. It is a matter of the availability of the driver in the distribution. I simply regret it is not available. It is a portable PC and replacing the GPU is not an option. The idea for me is to make this PC last longer.

Note that this old portable PC works very fine, not using the GPU, and with an external usb wifi card, because drivers have been removed from the newest distribution. The problem is on another PC, the most recent and powerful I assembled to be able tho handle the blender file my daughter, artist, sculpts with Blender.

I remind the configuration concerned:

Operating System: Kubuntu 26.04
KDE Plasma Version: 6.6.4
KDE Frameworks Version: 6.24.0
Qt Version: 6.10.2
Kernel Version: 7.0.0-15-generic (64-bit)
Graphics Platform: Wayland
Processors: 32 × Intel® Core™ i9-14900KF
Memory: 128 Gio of RAM (125.6 Gio usable)
Graphics Processor: NVIDIA GeForce RTX 3090

You do not face this behavior in your system, so do I with other PCs I have, different GPU, different hardware. Nevertheless, I face that problem with this PC. A new user have the same problem, the same error in the logs. I cannot tell you more, but I am ready to provide all information you request to identify the problem.

I even chance the drivers of the GPU drivers form 595 to 580 just to test if it was linked to the new version of the driver, and it did not change anything.

I change PC to provide all the details, tell me if you want more.

13

Here is everything installed on the PC

Here is the full conf of the PC with different tools

Note that this conf has been extracted with a X11 session, not a wayland session.

Tell me if you need more (syslog etc)

14

pgarcia@pascal-fixe:~$ journalctl -p3 -xb --no-hostname
mai 22 13:37:10 kernel:
mai 22 13:37:12 systemd[1]: Failed to start apparmor.service - Load AppArmor profiles.
░░ Subject: L’unité (unit) apparmor.service a échoué
░░ Defined-By: systemd
░░ Support: Enterprise open source support | Ubuntu
░░
░░ L’unité (unit) apparmor.service a échoué, avec le résultat failed.
mai 22 13:37:13 systemd[1]: Failed to start apparmor.service - Load AppArmor profiles.
░░ Subject: L’unité (unit) apparmor.service a échoué
░░ Defined-By: systemd
░░ Support: Enterprise open source support | Ubuntu
░░
░░ L’unité (unit) apparmor.service a échoué, avec le résultat failed.
mai 22 13:37:13 rsyslogd[2273]: cannot create ‘/var/spool/postfix/dev/log’: No such file or directory [v8.2512.0 try https://www.rsyslog.com/e/2176 ]
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error(s) opening ddc devices
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-1
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-2
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-3
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-4
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-5
mai 22 13:37:35 obexd[4090]: Unable to acquire registry: Error calling StartServiceByName for org.gnome.evolution.dataserver.Sources5: Unit evolution-source-registry.service not found.
mai 22 13:37:35 obexd[4090]: Unable to acquire registry: Error calling StartServiceByName for org.gnome.evolution.dataserver.Sources5: Unit evolution-source-registry.service not found.
mai 22 13:37:36 bluetoothd[2174]: src/adv_monitor.c:btd_adv_monitor_power_down() Unexpected NULL btd_adv_monitor_manager object upon power down
mai 22 13:38:50 systemd[1]: Failed to mount NasPGA-Homes.mount - /NasPGA/Homes.
░░ Subject: L’unité (unit) NasPGA-Homes.mount a échoué
░░ Defined-By: systemd
░░ Support: Enterprise open source support | Ubuntu
░░
░░ L’unité (unit) NasPGA-Homes.mount a échoué, avec le résultat failed.
p
pgarcia@pascal-fixe:~$ journalctl -p3 -xb --no-hostname
mai 22 13:37:10 kernel:
mai 22 13:37:12 systemd[1]: Failed to start apparmor.service - Load AppArmor profiles.
░░ Subject: L’unité (unit) apparmor.service a échoué
░░ Defined-By: systemd
░░ Support: Enterprise open source support | Ubuntu
░░
░░ L’unité (unit) apparmor.service a échoué, avec le résultat failed.
mai 22 13:37:13 systemd[1]: Failed to start apparmor.service - Load AppArmor profiles.
░░ Subject: L’unité (unit) apparmor.service a échoué
░░ Defined-By: systemd
░░ Support: Enterprise open source support | Ubuntu
░░
░░ L’unité (unit) apparmor.service a échoué, avec le résultat failed.
mai 22 13:37:13 rsyslogd[2273]: cannot create ‘/var/spool/postfix/dev/log’: No such file or directory [v8.2512.0 try https://www.rsyslog.com/e/2176 ]
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error(s) opening ddc devices
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-1
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-2
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-3
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-4
mai 22 13:37:34 org_kde_powerdevil[4010]: [ 4010] Error EACCES(-13): Permission non accordée opening /dev/i2c-5
mai 22 13:37:35 obexd[4090]: Unable to acquire registry: Error calling StartServiceByName for org.gnome.evolution.dataserver.Sources5: Unit evolution-source-registry.service not found.
mai 22 13:37:35 obexd[4090]: Unable to acquire registry: Error calling StartServiceByName for org.gnome.evolution.dataserver.Sources5: Unit evolution-source-registry.service not found.
mai 22 13:37:36 bluetoothd[2174]: src/adv_monitor.c:btd_adv_monitor_power_down() Unexpected NULL btd_adv_monitor_manager object upon power down
mai 22 13:38:50 systemd[1]: Failed to mount NasPGA-Homes.mount - /NasPGA/Homes.
░░ Subject: L’unité (unit) NasPGA-Homes.mount a échoué
░░ Defined-By: systemd
░░ Support: Enterprise open source support | Ubuntu
░░
░░ L’unité (unit) NasPGA-Homes.mount a échoué, avec le résultat failed.
p

Obvioously I have some details to solve apparmor, postfix messages (postfix not installed !), this i2c problem, and the nas that is not switched on. But I think noting related to the problem.

15

I solved some minor problems on my system, mostly configuration of apparmor, some file having disappeared. And I test again a wayland session just in case.

Nothing changed, but I noticed error around XP-Pen tablet only with wayland session. Then I plug in the tablet (Xp-pen Artist 15.6 Pro) , disconnect a reconnect the session, and reboot. No change for the taskbar but the error messages related to the XP-Pen tablet in the logs are gone.

But I noticed also few things. First the resolution of my screens is way over the resolution the screens are documented to support (2560×1440 instead of 1920×1080). Difficult to believe. When I want ta arrange the screen of the tablet only in 1920x1080, its new position is not taken into account. The mouse move on the tablet always to the right of the right screen even if I choose to have it on the very left. The configuration by the Xp-Pen utility is not taken into account. There may be a conflict.

Note that with X11 all resolution screen are 1980x1024, no way to change for a higher resolution.

Obviously, according to what I saw on the Internet, Wayland and Xp-Pen are not compatible.

But I will make some more tests,

  • remove the XP-Pen drivers and utility, to see if this solves the problem of the task bar.
  • Play a bit with the resolution of the screens, this seems to me strange to be configured with these resolutions Quad HD definition.
16

Exactly one reason to stay away from unstable Wayland. I will die clutching my X11 in sweaty palms :slight_smile:

17

That is really a shame people have to take this position. Wayland is far more efficient with graphics, and in taking advantage of the recent hardware and GPU.

But as long as Wayland is not stable enough, that is a sensible choice. I read somewhere KDE would get rid of X11, I do not know if it is really the plan, but developers please maintain X11 session available. Without X11 session I would have no choice but to go to Windows on my recent PC because Wayland does not work on this PC.

I hope all these problems will be solved soon, but I believe that some are not trivial as known for ages.

I really think that Wayland is the future, at least the solution to use powerfull graphics, what is the first step to support the games, and I hope, have the game editors porting and developing their games on Linux, and then fill the gap to have Linux a viable solution to be adopted by everybody. Today players do not use Linux, cannot use Linux.

By the way, for XP-Pen tablet the problem of the resolution of the screen and the problem of the relative location of the screens on the desktop does only appear when the tablet is plug-in and with Wayland. Everything works fine with X11. I believe pluging the tablet activates the drivers of the tablet that introduces conflicts.

18

I sometimes feel that humanity is burning out, in so many arenas it seems people are only capable of taking extreme views…

X11 works fairly well, switching back to it, I can still use Mouse Gestures (with Easystroke) which gives an incredible way of driving a desktop (i.e. window operations, switching tabs, closing/reopening stuff… it’s all a flick of the mouse - easier than keyboard shortcuts even).

If there’s a reason it cannot work for you, then by all means - skip using Wayland for now… but there’s no excuse for condemning the single best hope for the future of our systems.

X11 was great in many ways - and inferior to Windows in many ways.

Wayland is simply a much better prospect. You can report that it doesn’t work for you, but ther’s certainly no call for utter condemnation.

Meanwhile, Wayland has proved itself as a stable platform, and I trust it will pick up some more of those missing features that most of us crave.