SDDM Theme broken after update to Plasma 6 with no way to change it back?

Hello, after upgrading to KDE Plasma 6, my SDDM theme no longer works. I was using a custom theme, which probably isn’t compatible with KDE Plasma 6. That’s okay, I could just change it back to the default breeze theme, but there is no SDDM setting in plasma settings like it used to in Plasma 5.

What can I do to fix SDDM?

Here is the error message, though it’s probably not necessary for what I need help with:

The current theme cannot be loaded due to the errors below, please select another theme.
file:///usr/share/sddm/themes/KDE-Story-Blue-SDDM/Main.qml:111:9: Type WallpaperFader unavailable
file:///user/share/sddm/themes/KDE-Story-Blue-SDDM/components/WallpaperFader.sml:13:1: module "org.kde.plasma.private.sessions" is not installed.

SDDM works fine, but it has that weird look that occurs when the theme does not work.

Comment deleted…

I worked around this issue by rolling back, changing the theme and then updating again.

Now DPI Scaling is broken but that’s unrelated.

The issue is because the kcm_sddm package isn’t updated to plasma 6 so it isn’t compatible. I have made a bug report so it should get fixed eventually.

1 Like

kcm_sddm has not been built for KDE 6. It explicitly depends on and requires KDE 5.

1 Like

Looks like the last update broke most of the themes. My solution was just install sddm-conf and change the theme for the default breeze. It’s a cheap solution but looks better than that weird login screen.

Package should get updated soon: 1217188 – AUDIT-WHITELIST: sddm-kcm6: new revision of D-Bus service org.kde.kcontrol.kcmsddm.conf

Hi, I think i have the same problem.

With what theme did you change it with?

What are all the things that you changed and with what in order to make it work? :+1:

I changed it to the default Breeze theme. That one works even after the upgrade.

I rolled back to KDE Plasma 5 using snapper, where the sddm_kcm package still worked, changed sddm theme to breeze, pressed Ctrl + Alt + F4 to switch to a CLI environment and updated my system to KDE Plasma 6, then rebooted using systemctl reboot.

Luckily rolling back isn’t necessary anymore. sddm_kcm package is now available in KDE Plasma 6, so just update and you should be able to change your theme in the settings like normal. Change it to the default breeze theme or the openSUSE breeze theme. Both work fine.

1 Like

never mind…I see you found sddm-kcm6.

Yes, this topic was made before they migrated it to KDE Plasma 6 so at that time you couldn’t change the broken theme.

It worked!

I tried it again and I did it as you said.

I was already using Breeze but the dark one so I switched to the light one. Then I switched my screen from dual monitor setup only to one to make sure to have no Plymouth issue or such .
Then I upgraded with sudo zypper dup and I was able to log in even without restart!

Of course, I have restarted and it works fine both on X11 and Wayland (at least so far)

I think I will still main on X11 for some time as I am used to it and perhaps a little more stable still.

1 Like

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.