Bug 381904

What error message is shown?

(In reply to Martin Flöser from comment #1)
> What error message is shown?

The lock screen says "Unlocking failed"

Is there anything special about your password authentication? Are you maybe using a multi stage authentication? Or do you have "special" characters in your password? Did you reconfigure the password in any way since installation?

The problem appeared right after the installation on both machines. None of them uses special characters in the password (only letters and numbers). I made sure num lock was on, and caps lock wasn't (anyway I can see what I'm typing on the text field and it's the right password).

Each computer has a different password, both have the problem.

Also, I don't know what multi stage authentication is: I just have one password which works everywhere except on the lock screen. I can use sudo, login (console and UI), only the lockscreen doesn't work.

I don't know if it changes anything, but I installed the OS with a kde neon 5.10.2 usb, and upgraded to 5.10.3 right after the install (did not try if the lock screen was working before).

with multi stage I meant e.g. finger print reader in addition to password.

Can you try to run:
/usr/lib/x86_64-linux-gnu/libexec/kscreenlocker_greet --testing

from a command line and check whether the password is accepted there?

Still not working. Here's the console output:

>>>/usr/lib/x86_64-linux-gnu/libexec/kscreenlocker_greet --testing
org.kde.kcoreaddons: Failed to establish shared memory mapping, will fallback to private memory -- memory usage will increase
file:///usr/share/plasma/wallpapers/org.kde.slideshow/contents/ui/main.qml:147: TypeError: Property 'setAction' of object ScreenLocker::WallpaperIntegration(0x1ce4ce0) is not a function
Locked at 1499005024
No file found for ".xml" , even though update-mime-info said it would exist.
Either it was just removed, or the directory doesn't have executable permission... ("/home/keplyx/.local/share/mime", "/usr/share/mime")
No file found for ".xml" , even though update-mime-info said it would exist.
Either it was just removed, or the directory doesn't have executable permission... ("/home/keplyx/.local/share/mime", "/usr/share/mime")
org.kde.kcoreaddons: Failed to establish shared memory mapping, will fallback to private memory -- memory usage will increase
UdevQt: unable to create udev monitor connection
WARNING: Cannot find style "org.kde.desktop" - fallback: "/usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Base"
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/lockscreen/LockScreenUi.qml:98:103: Unable to assign int to QEasingCurve
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
Authentication failure
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
Authentication failure
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"
No metadata file in the package, expected it at: "/home/keplyx/Pictures/Wallpapers/"

For both Authentication failure, I entered the correct password.

Reassigning to Neon. Authentication failure is printed by kcheckpass in case something is wrong with PAM. Please verify that all required files for the PAM interaction are installed. It's the only idea I have on why it's failing here.

ok thanks you for the help!

I have the following packages containing pam:

pam-auth-update        pamfile                pamstretch-gen
pamcut                 pam_getenv             pam_tally
pamdeinterlace         pamoil                 pam_tally2
pamdice                pamon                  pam_timestamp_check
pam_extrausers_chkpwd  pamstack               
pam_extrausers_update  pamstretch

pam-auth-update seems to be the one you are talking about, but I don't know how to check if the required files are installed.

Same problem here on ArchLinux 32bit after updating to kscreenlocker-5.10.3. But many other packages are also updated. The last working version was 5.10.2.

After entering the password to unlock, the screenlocker screen disappears and I get a black screen where I can see and move the mouse pointer around. Nothing can be typed or clicked.

I've checked the password with '/usr/lib/kscreenlocker_greet --testing'.

To unlock I use (more or less the same method as in comment #1):
loginctl unlock-sessions && killall -9 kscreenlocker_greet

Fixed the problem by reinstalling a fresh kde neon 5.10.3 (Last modified 06-Jul-2017 11:58) from : https://files.kde.org/neon/images/neon-useredition/current/

My first installation ISO had a problem (root folder not owned by root but by user 1000000), which must be the reason the screenlocker wasn't working as expected.