At a quick glance, the Sweet Ambar Blue SDDM theme has two versions – one for Plasma 5 and another one for Plasma 6. You probably want the one for Plasma 6. You can check which version of Plasma you’re running in System Settings -> About this System -> KDE Plasma Version.
Be extremely careful when installing Plasma/SDDM themes. They are user-submitted, not always reviewed, and can contain arbitrary code. There have been incidents involving
maliciousdamaging code downloaded through Plasma global themes.There have been incidents involving malicious code downloaded through Plasma global themes.
No malicious code was involved, just buggy code.
As the message is saying, you should try installing QtQuickControls
Have you tried
sudo dnf upgrade QtQuick.Controls
Then Reboot If that doesn’t worksudo dnf reinstall QtQuick.Controls
Reboot again Still no worky Try moving the theme file out of the share folder and reassigning the directory to the new location Then reboot Post any error messages received in terminalYou are on Plasma 6 and seemingly all SDDM themes are currently broken.
Use the default theme and try to find ones that work.
When I upgraded to Plasma 6, I needed to select default theme, upgrade, then re choose my theme. Also upgraded from command line rather than a terminal window.
Have you tried reinstalling sddm and/or the theme? Had the same kind of error a few weeks ago were reinstalling did the trick for me
Just a suggestion…if you’ve enabled disk encryption during installation, consider enabling autologin for SDDM so you’re not having to enter two credentials at boot. You’ll rarely ever see your greeter again, so it won’t really matter which theme is used.
And if you did not enable disk encryption, consider doing so as the security and privacy benefits are significant for most users.
I’ve had some VERY similar issues with SDDM ever since I switched to Fedora 40 Sway. Only my issue is with Qtgraphicaleffects, while quickcontrols seems to load properly. I have the following package:
qt5-qtquickcontrols2
installed with dnf and it works. Hope it works for you too. But for me, I’m still having Qtgraphicaleffects issues, to the point I ended up rewriting my sddm theme without Qtgraphicaleffects. It’s crazy, I know, but it’s hard enough to find a decent theme without KDE dependencies as it is (I’m not using KDE Plasma). Finding one without qtgraphicaleffects as well would be even harder.Shoo, it’s been a rough week for sddm over here…
Moral of the story. Don’t run Fedora 🥶