Bug 2375328

Summary: KDE screen locking since 6.4.1 results in "The screen locker is broken" screen
Product: [Fedora] Fedora Reporter: Walter Francis <wally>
Component: kscreenlockerAssignee: KDE SIG <kde-sig>
Status: CLOSED EOL QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: urgent Docs Contact:
Priority: unspecified    
Version: 41CC: dawson, e.n.taylor.67, kde-sig, lpancescu, pg_forums, rdieter, redhatbugzilla, sbonazzo, udippel
Target Milestone: ---Keywords: Desktop, Regression
Target Release: ---   
Hardware: x86_64   
OS: Linux   
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Fixed In Version: Doc Type: ---
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Last Closed: 2025-12-17 05:29:03 UTC Type: Bug
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Walter Francis 2025-06-28 14:20:41 UTC
Description of problem:
Upon update to 6.4.1, as far as I can tell, existing and new users as soon as the screen locker kicks in, you get the "The screen locker is broken" screen forcing users to do silly stuff to log back in.

Per a thread I found on Reddit there is a workaround to go into System Settings, Screensaver, Appearance, and set any wallpaper and apply.  As for what's actually causing the issue I do not know.

Version-Release number of selected component (if applicable):
6.4.1

How reproducible:
100% for new installs, new, and existing users

Steps to Reproduce:
1. Update
2. Lock screen
3. Wonder why KDE made this lock screen make you do silly stuff to log back in

Actual results:
Broken screen telling you to go to the console to log back in.

Expected results:
Lock screen works, lets you log back in.  Handles minor exceptions like whatever is causing this.

Additional info:
Stomach acid is strong enough to melt metal

Comment 1 Laurentiu Pancescu 2025-06-28 18:32:46 UTC
I have a mini-PC configured to suspend after 15 minutes. Besides the "unable to lock, use loginctl unlock-session N" issue described by Walter, when the mini-PC wakes up from suspend, the entire KDE Plasma session is gone, including all programs that were running in it, and abrt-applet prompts me to report a crash in each of the running program.

Clicking a wallpaper in System Settings, as described by Walter, solves both the "use loginctl" and the "session dies on suspend" issues for me.

Comment 2 pg_tips 2025-06-28 22:14:44 UTC
qt6-qtwayland 6.9.1-2 seems to be involved here: https://bugzilla.redhat.com/show_bug.cgi?id=2375356

With that reverted to 6.9.1-1, and nothing else reverted (i.e. all Plasma-related packages at their latest version), I don't get this issue at all.

If I reupgrade qt6-qtwayland to 6.9.1-2 again, and don't touch any other packages. the lockscreen issue comes back.

Comment 3 udippel 2025-06-29 13:37:31 UTC
I cannot confirm some here:

1. I had a wallpaper set, and yet was hit by this.
2. After logging in through ssh, and unlock the session, everything was up as of before, luckily. 
3. My workaround is to simply set the screen lock to "Never".

I *think* I could not reach a virtual console, like what was suggested on the black screen. I am not sure, because I was nervous since I had some process running for a few hours and was most keen to not lose it.

Comment 4 pg_tips 2025-06-29 13:44:58 UTC
The "broken screenlocker" screen suggests Ctrl-Alt-F1 for a virtual console, which on most Fedora installs I think won't work. Ctrl-Alt-F3 should work.

Downgrading qt6-qtwayland to 6.9.1-1 should resolve the issue: a couple of methods are suggested in comments at https://bugzilla.redhat.com/show_bug.cgi?id=2375356

btw my own experience was that changing the wallpaper seemed to mitigate the issue for a short time, but until I downgraded qt6-qtwayland, the lockscreen issue kept coming back: I didn't figure out exactly what conditions retriggered it.

Comment 5 pg_tips 2025-06-30 07:15:38 UTC
A related bug https://bugzilla.redhat.com/show_bug.cgi?id=2375438 appears to have been raised against layer-shell-qt. I don't have access to it, but I guess Red Hat folks may.

Comment 6 Dawson 2025-07-03 22:13:28 UTC
Running Fedora 42 with KDE plasma desktop on 2024 HP laptop with 32GB ram - no virtual session.  None of the Function keys seem to allow exit from error screen and hard shutdown seems to be only option.  

Deprecating to earlier version qt6-qtwayland-6.9.1-2.fc42 that appears to work for now but await testing on a released fix.

Comment 7 pg_tips 2025-07-04 06:14:57 UTC
(In reply to Dawson from comment #6)

> Deprecating to earlier version qt6-qtwayland-6.9.1-2.fc42 that appears to
> work for now but await testing on a released fix.

6.9.1-3.fc42 (which reverts the problematic change in 6.9.1-2 and restores the ABI of 6.9.1-1) has now been released into stable Fedora 42.

https://bugzilla.redhat.com/show_bug.cgi?id=2375356#c33

Comment 8 Adam Williamson 2025-12-02 03:10:51 UTC
This message is a reminder that Fedora Linux 41 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora Linux 41 on 2025-12-15.
It is Fedora's policy to close all bug reports from releases that are no longer
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Comment 9 Samyak Jain (RedHat) 2025-12-17 05:29:03 UTC
Fedora Linux 41 entered end-of-life (EOL) status on 2025-12-15.

Fedora Linux 41 is no longer maintained, which means that it
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