[Desktop] K-Win frequently crashes when the PC starts up

[greenster]

For the past few days, K-Win has been crashing frequently when I start up my PC.

Unfortunately, I can’t send an error report.

That’s why I’m asking here.

[greenster]

KWin continues to crash every time I restart Kubuntu 26.04 LTS. The standard Kubuntu taskbar at the top of the desktop does not appear, but another taskbar at the bottom does appear as normal.

How can I fix this problem?

Would it be helpful for you to see the error code for the KWin crash? If so, what’s the best way for me to provide it?

[die.boer]

After a reboot where KWin crashed, run:

journalctl -b -1 | grep -Ei "kwin|plasmashell|drkonqi|segfault"

if it crashed during the current boot,run:

journalctl -b | grep -Ei "kwin|plasmashell|drkonqi|segfault"

paste the output

also check whether KWin is actually crashing

coredumpctl list | grep kwin

If you see entries, also run:

coredumpctl info

and paste the KWin section

[greenster]

One more thing: if Kubuntu starts up with errors like that, I log out and then log back in, and Kubuntu starts up normally again without any errors.

@die.boer I’ll get round to your tasks later today.

[die.boer]

One more thing: if Kubuntu starts up with errors like that, I log out and then log back in, and Kubuntu starts up normally again without any errors.

with that info ,please try disabling session restore.(if it is enabled)

Go to:

System Settings - Session - Desktop Session

and set: On login: Start with an empty session

[greenster]

with that info ,please try disabling session restore.(if it is enabled)

Go to:

System Settings - Session - Desktop Session

and set: On login: Start with an empty session

That’s exactly how it was already set up for me.

[greenster]

When the system shuts down, I can see that my Kubuntu is labelled ‘Development branch’.

Does that mean this is a developer version of Kubuntu and that errors might therefore occur?



I downloaded Kubuntu from here in February this year:

https://wiki.ubuntuusers.de/Downloads/Resolute_Raccoon/

[die.boer]

The official release of Ubuntu/Kubuntu 26.04 LTS wasn't available yet in February, so the ISO you installed was almost certainly a pre-release (daily build/beta). Those builds identify themselves as the development branch.

Even though you've kept it updated, some packages or branding may still reflect that development state, and pre-release installations can occasionally carry over bugs or configuration quirks.
That does not necessarily explain the KWin crashes,but it does increase the likelihood that you're encountering a Plasma or packaging bug that wouldn't affect someone who installed from the final release media.

please give outputs of these 2

cat /etc/os-release

apt policy base-files

...and the error codes from post #3 , if possiible