Plasma crashes at login on Kubuntu 26.04

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1

Hi,

I’m using an up-to-date installation of Kubuntu 26.04 on my personal desktop PC.

For about a week, Plasma has been crashing every time I log in. The screen flickers approximately every five seconds, the panel and desktop icons are missing, and only the crash-report window appears. A new crash window is displayed each time, so they gradually pile up.

I can still open a terminal with Ctrl + Alt + T.

While troubleshooting with the help of AI, I found that the problem seems to be related to the .cache directory. When the crash occurs, I open a terminal, delete .cache, and reboot. Plasma then works normally—but only until the next reboot. The problem comes back, and I have to delete .cache again.

How can I continue diagnosing this issue properly? What logs or commands should I check to identify which component is causing the crash? More importantly, how can I fix the underlying problem instead of repeatedly deleting .cache?

Thank you for any suggestions.

2

Are you a Chrome user? A recent update to the browser seems to be mucking up the font cache.

It seems to be affecting some Fedora and Kubuntu users, if not others.

See here for more discussion.

Clearing out the font cache (which is in ~/.cache) as you are doing should fix it, so just avoid using Chrome until Google push out a fix.

3

it may be even longer if the browser is chromium based like brave

4

None of the ones I see so far are using 154 yet, so they may miss causing the issue altogether if they use an embedded fontconfig as Chrome proper does.

…or I spoke too soon :frowning:

5

I confirm using Brave browser. Thanks for the answer, I’ll take a look. I hope they don’t pass the hot potato back and forth between the Chromium and KDE developers.

6

Direct-access workaround here, while waiting for the patch in Brave and other Chromium-based browsers.

If the session crashes on startup, open terminal with Ctrl+Alt+T:

rm -rf ~/.cache/fontconfig && fc-cache -f

As a temporary fix, create an executable script containing:

rm -rf ~/.cache/fontconfig && fc-cache -f

In KDE’s settings, go to Autostart, choose Script to run at logout and select this script.