Kubuntu 24.04 LTS screen goes black after running fine for a while.

[jadaml]

I have a rather specific issue with my Kubuntu installation that I cannot properly search for, and even have difficulties to explain.

Not sure if this relevant:
I have used Ubuntu before on my PC, but I preferred to use Windows. Later I have decided to switch from Windows, and decided to install Kubuntu, since after trying both Gnome and KDE, I preferred the later. I have originally installed Kubuntu 22.04 LTS, few days before the Kubuntu version 24.04 was released (or I have missed the latest release). I have recently updated to 24.04 LTS, but with the desire to try out Amarok, I have added a source, and made the mistake to update all packages, and Ubuntu reported development version of 24.10. I have, of course, reinstalled Kubuntu 24.04 LTS leaving the Home partition in place.

Now, after installing back the applications, whenever the system is running a while, it looses (resets?) the audio device, and after a few seconds from then, the entire screen goes black, seemingly like X server just restarts, and only the cursor is visible. I tried the proprietary NVidia driver as well, but that didn't work either. I tried to search "Kubuntu 24.04 black screen" but any results I've found is about the system starting with a black screen, without it ever showing the desktop. Despite using Linux for quit a while now, I still can't get the hang of the utilities to trouble shoot the system. Could you help me troubleshoot this issue? What should I do to assess the situation when the issue occurs next time, to gain understanding of it?

---

Operating System: Kubuntu 24.04
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.13
Kernel Version: 6.8.0-41-generic (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-4820K CPU @ 3.70GHz
Memory: 15.6 GiB of RAM
Graphics Processor: NV166

NVidia RTX 2070

[jadaml]

I have done two things since, to make things bearable:

1. I've enabled Ctrl+Alt+Backspace to restart the X server, for whenever it needs to be restarted,
2. Disabled the Kompositor with Alt+Shift+F12, as that seemed one of the culprit:
   The energy option to turn off the screen seems to trigger this issue for me, according to my latest observation.
   Hibernation also seems to trigger similar issues, but not sure on that yet.

I'm back to square one. I do not know what is the issue. Maybe after restarting the X server, this start to work correctly?

[jlittle]

... seemingly like X server just restarts, and only the cursor is visible...

That's like plasma has crashed. You could try

• Press Ctrl-Alt-F3 to get a Linux console, and login
• run

  DISPLAY=:0 plasmashell --replace &

• Press Ctrl-Alt-F2 to get back to plasma

Of course that's not a solution. plasmashell normally logs to the systemd journald log, so you can see what it says with

journalctl --since -30m /usr/bin/plasmashell

for the last 30 minutes. (If you restart plasmashell as above, messages appear in the Linux console.)

[jadaml]

Thank you very much for your help! It took me a while to reproduce issue, but when it happened, it was quite an inappropriate time, so I immediately hit Ctrl+Alt+Backspace instead. (I don't know if this does the same though.) I follow these steps next time when happens. Never the less, I've collected some information now, and tried to look in to it on other forums.

What happened, is that I saw the audio driver "detach," and then, while I was quitting the applications, a few seconds later, the screen went after it. I did not wait much before smashing Ctrl+Alt+Backspace. This is the output of journalctl --since -30m /usr/bin/plasmashell after the login appeared:

szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_output.pci-0000_00_1b.0.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: file:///usr/share/plasma/plasmoids/org.kde.plasma.volume/contents/ui/ListItemBase.qml:119: TypeError: Value is undefined and could not be converted to an object
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_output.pci-0000_00_1b.0.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_input.usb-046d_Brio_500_2230LZ54UEJ8-02.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: file:///usr/share/plasma/plasmoids/org.kde.plasma.volume/contents/ui/ListItemBase.qml:119: TypeError: Value is undefined and could not be converted to an object
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_output.pci-0000_00_1b.0.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_input.usb-046d_Brio_500_2230LZ54UEJ8-02.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_output.pci-0000_00_1b.0.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_input.usb-046d_Brio_500_2230LZ54UEJ8-02.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_output.pci-0000_00_1b.0.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "alsa_input.usb-046d_Brio_500_2230LZ54UEJ8-02.5.analog-stereo"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "auto_null"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "auto_null.monitor"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "auto_null.monitor"
szept 16 15:46:27 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "auto_null.monitor"
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: context kaput
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "auto_null"
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: No object for name "auto_null.monitor"
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: org.kde.pim.akonadicore: "QLocalSocket: távoli lezárás" "/run/user/1000/akonadi/akonadiserver-ntf.socket"
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: org.kde.pim.akonadicore: "QLocalSocket: távoli lezárás" "/run/user/1000/akonadi/akonadiserver-cmd.socket"
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: org.kde.pim.akonadicore: Socket error occurred: "QLocalSocket: távoli lezárás"
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: file:///usr/share/plasma/plasmoids/org.kde.plasma.private.systemtray/contents/ui/items/PlasmoidItem.qml:125: TypeError: Cannot read property 'compactRepresentationItem' of null
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/osd/Osd.qml:24:15: QML OsdItem (parent or ancestor of QQuickLayoutAttached): Binding loop detected for property "preferredWidth"
szept 16 15:46:37 OBSIDIAN plasmashell[2787]: file:///usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/Footer.qml:155:5: QML LeaveButtons: Binding loop detected for property "shouldCollapseButtons"
szept 16 15:46:38 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: context kaput
szept 16 15:46:39 OBSIDIAN plasmashell[2787]: org.kde.plasma.pulseaudio: context kaput
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: The X11 connection broke: I/O error (code 1)
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: XIO:  fatal IO error 9 (Hibás fájlleíró) on X server ":0"
szept 16 15:46:40 OBSIDIAN plasmashell[2787]:       after 270943 requests (227708 known processed) with 0 events remaining.
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: file:///usr/share/plasma/plasmoids/org.kde.plasma.printmanager/contents/ui/printmanager.qml:63: TypeError: Cannot read property 'gridUnit' of null
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: file:///usr/share/plasma/plasmoids/org.kde.plasma.printmanager/contents/ui/printmanager.qml:64: TypeError: Cannot read property 'gridUnit' of null
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: KCrash: crashing... crashRecursionCounter = 2
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: KCrash: Application Name = plasmashell path = /usr/bin pid = 2787
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: KCrash: Arguments: /usr/bin/plasmashell --no-respawn
szept 16 15:46:40 OBSIDIAN plasmashell[2787]: KCrash: Attempting to start /usr/lib/x86_64-linux-gnu/libexec/drkonqi

If I analyze the logs based on what happened, I see that at 27 seconds is when the audio devices are lost, and 37 is what possibly where the screen is going blank. Following that on 38 seconds is the result of ctrl+alt+backspace, I will not search on that. I see that Plasma looses all the audio objects, then crashing, followed by Akonadi loosing access to... something. (I had installed some chat software at some point, but I don't have it installed right now.)

One forum post I saw, is referred to the https://bugs.kde.org/show_bug.cgi?id=469016#c63 bug, where they suggested to change the plasma renderer loop to threaded. For now, I try that and see what it does.

[jadaml]

After I've finished the post, and restarted, it crashed again with that change. Following those steps did not brought back Plasma, so I restarted the X server with Ctrl+Alt+Backspace. Should I check /usr/bin/kwin_x11 next time?

szept 16 17:53:05 OBSIDIAN plasmashell[2812]: kde.dataengine.mpris: "org.mpris.MediaPlayer2.chromium.instance8717" has an invalid URL for the mpris:artUrl entry of the "Metadata" property
szept 16 18:17:19 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "alsa_input.usb-Logitech_PRO_000000000000-00.mono-fallback"
szept 16 18:17:19 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "alsa_output.usb-Logitech_PRO_000000000000-00.analog-stereo"
szept 16 18:17:19 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "alsa_input.usb-Logitech_PRO_000000000000-00.mono-fallback"
szept 16 18:17:19 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "auto_null"
szept 16 18:17:19 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "auto_null.monitor"
szept 16 18:17:19 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "auto_null.monitor"
szept 16 18:17:19 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "auto_null.monitor"
szept 16 18:17:29 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: context kaput
szept 16 18:17:29 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "auto_null"
szept 16 18:17:29 OBSIDIAN plasmashell[2812]: org.kde.plasma.pulseaudio: No object for name "auto_null.monitor"
szept 16 18:17:29 OBSIDIAN plasmashell[2812]: file:///usr/share/plasma/plasmoids/org.kde.plasma.private.systemtray/contents/ui/items/PlasmoidItem.qml:125: TypeError: Cannot read property 'compactRepresentationItem' of null
szept 16 18:17:29 OBSIDIAN plasmashell[2812]: org.kde.pim.akonadicore: "QLocalSocket: távoli lezárás" "/run/user/1000/akonadi/akonadiserver-ntf.socket"
szept 16 18:17:29 OBSIDIAN plasmashell[2812]: org.kde.pim.akonadicore: "QLocalSocket: távoli lezárás" "/run/user/1000/akonadi/akonadiserver-cmd.socket"
szept 16 18:17:29 OBSIDIAN plasmashell[2812]: file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/osd/Osd.qml:24:15: QML OsdItem (parent or ancestor of QQuickLayoutAttached): Binding loop detected for property "preferredWidth"
szept 16 18:17:29 OBSIDIAN plasmashell[2812]: org.kde.pim.akonadicore: Socket error occurred: "QLocalSocket: távoli lezárás"​

Edit: I've just realized, that Akonadi is used Kontact, that I've installed so the "taskbars" calendar can show events from my calendar.

[jadaml]

I do not know if the two related, but it seems to fixed this issue for me.

Before I've posted this issue, I have migrated my home partition from one drive to another, and used CloneZilla for it. However, only recently noticed, that this kept the partition's UUID the same, which is a problem, since my old drive is also still in my PC, having two partitions on different drives share the same UUID. Since I've assigned a new UUID to the new partition, the above issue seems to disappear. Another partition is the /boot/efi, but I have since removed the old partition.

These drives are HDD's and not SSD's, and I've did this migration, because the original HDD's SMART status reported several bad sectors (two digits) and I did the migration as a precaution.