Created attachment 123325 [details]
The journalctl log when the screen locker started.  The "broken" msg came on around 14:13.

SUMMARY
The latest KDE updates seem to have broken the screen locker.  After the screen locker starts, it eventually crashes.  Sometimes it happens after a few minutes, sometimes after a lot of minutes.  When it crashes, the screen goes black & has a "broken" message saying this:

Screen locker is broken and unlocking is not possible anymore.
In order to unlock, switch to a virtual terminal Ctrl+Alt+F2 and execute
loginctl unlock-session 2.
Afterwards switch back to the running session Ctrl+Alt+F1

STEPS TO REPRODUCE
1. Let the screen locker come on.
2. 
3. 

OBSERVED RESULT
The screen locker crashes after a random amount of time.  It always crashes eventually.

EXPECTED RESULT
The screen locker should stay on without crashing.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Arch Linux Kernel Version: 5.3.6-arch1-1-ARCH
(available in About System)
KDE Plasma Version: 5.17.0
KDE Frameworks Version: 5.63.0
Qt Version: 5.13.1

ADDITIONAL INFORMATION
In my case, I have the screen locker set to slideshow.  It changes images every 10 seconds.  It works fine displaying & showing the images, but eventually, it will crash & show the "broken" message described above.  I'm including an attachment of the journalctl log after the screen locker started.  The screen locker was working like normal until it crashed & showed the "broken" message at around 14:13.  I logged back in about 2 minutes later.