Plasmashell not loading

[JamesKB]

OS: 26.04

This just started this morning. When I turn on the computer this is what happens:

1. I get the login screen
2. I enter my password
3. I get the "K" plasma screen
4. The wallpaper displays
5. Then I get this dialog: plasmashell-Crash Handler plasmashell has closed unexpectedly.
6. I close that dialog
7. I get a blank black screen, the mouse is still active
8. I press the computer power button
9. The login screen displays again, and I start all over with the same results.

I can send screen shots if that will help.

Any ideas? Thank you for your time.
--
James

[troymcclure]

I found this solution, and so far, I haven't experienced the error again.

https://dev.to/zerolock/kde-plasma-c...ition-fix-2ebm

[Snowhog]

Nice find!

[Snowhog]

AI Overview

When plasmashell crashes immediately after loading your desktop wallpaper, it is usually caused by a corrupted cache, an incompatible widget/plasmoid, or a broken dynamic wallpaper plugin (like a third-party Wallpaper Engine script). [1, 2]

Because the underlying window manager (kwin) is still running, you can interact with your system using keyboard shortcuts. Follow these structured steps to resolve the crash loop: [1]

Step 1: Open a Terminal or Command Prompt

Press Ctrl + Alt + T on your keyboard to open Konsole.
(If that doesn't work, press Alt + F2 to open KRunner, type konsole, and press Enter). [1, 2, 3]

Step 2: Reset the Corrupted Wallpaper Configuration

A broken wallpaper setting or corrupted layout file is the most common culprit behind crashes at this exact phase. [1]

• Back up and reset your desktop configuration by running this command in the terminal: bash
  
  mv ~/.config/plasma-org.kde.plasma.desktop-appletsrc ~/.config/plasma-org.kde.plasma.desktop-appletsrc.bak
  
  Use code with caution.

• Clear the Qt/Plasma cache, which can harbor corrupt interface layouts: [1]
  
  rm -rf ~/.cache/plasmashell* ~/.cache/org.kde.dirmodel-qml.kcache
  
  Use code with caution.

Step 3: Restart Plasmashell

Force Plasma to rebuild your desktop panel and default layout using the new configuration: [1]

systemctl --user restart plasma-plasmashell.service

Use code with caution.

(Alternatively, you can run plasmashell --replace &)

[claydoh]

Maybe add the very recent font cache corruption many are seeing, possibly caused by Chrome?

https://www.reddit.com/r/Kubuntu/com...rome_corrupts/

[JamesKB]

Thanks for the response. However, it did not work. I entered each command as shown above but the issue still remains. More ideas??

[JamesKB]

This is the error message I get after entering the bash commands listed above:

[JamesKB]

At the end of the error message line, I see this:

“ should be Qlist(“ui/main.qml”)

What is this about??

Ideas??

[troymcclure]

I found this solution, and so far, I haven't experienced the error again.

https://dev.to/zerolock/kde-plasma-c...ition-fix-2ebm

[Snowhog]

Nice find!

[skyfishgoo]

fc-cache -r

don't use chromium based browsers like brave until this gets sorted.

[claydoh]

It is possibly even simpler to work around.

The main bug cause is specifically from Chrome updating its built-in fontconfig version writing cache files that the system fontconfig and/or Qt do not like. This got picked up by at least Brave a day or so later. Possibly by some Electron or similar PWA apps are a possibility.

And this affects more than just Kubuntu 26.04. Fedora is seeing it as well (they use the same fonctofig version as 26.04, but use a more current Qt). Even if the ultimate cause is fontconfig and Qt versions, neither of these have been updated in *buntu since April.

The interesting part is that it does not seem to affect everyone. My Kubuntu 26.04 does not suffer from it at all. Nor has my one test of a fresh install.

On my KDE neon system (newer Qt but stock 24.04 fontconfig), it does not crash but has had the panel freeze, but not every boot. I am assuming it is the Chome update, as this is when it started.

I have modified my Chrome launcher to have it use a separate font cache dir as someone has suggested on the Brave bug report. Something along these lines:

env XDG_CACHE_HOME=/home/<user>/.cache/chrome-isolated​​

Edit as you need to for your username, etc.
You can use the KDE menu editor for this, add it to the "command-line" or similar section, then clear the cache:

mv ~/.cache/fontconfig ~/.cache/fontconfig.old && fc-cache -f​

I have not seen my panel freeze since, but again, it may not have been the cause, and it has been somewhat intermittent to begin with.


Now, if one uses *ALL* the Chromium-based browsers, the systemd service is probably the easier route compared to editing multiple menu entries.

[cookiemuncher]

I am running Kubuntu 26.10 and that crashed a few times as well. Removing ~/.cache/fontconfig and Chrome seems to prevent the issue. We will see.

[JamesKB]

I followed the link provided by troymcclure the instructions there fixe the issue. Thanks for the tip.