Do you see any window "We appologise..." drKonqi second tap to copy backtrace in pastebin or similar site. Or you make a mistake and run plasmashell with sudo ? Don't do that because config and cache files will be owned by root. Alt+f2 type konsole -> enter

kquitapp5 plasmashell
sudo rm -f ~/.cache/plasma*

Now alt+f2 type plasmashell, it should run. 🙂

Thanks, I hope the mistake will never come back. I don't now what happened with plasmashell??

I have installed a new printer, but the scanner will not be installed. Was that the mistake???
I've read the instructions, but I'm not really smart. My multi-functional printer Epson WF-2760 DWF is not connected via USB but as a network printer. Printing works. I do not get any scanner drivers for KaOS, I have for Fedora * rpm file. Do not know how I can make it all work. Have also no programming learned.

New problem after restart and crashed plasmashell:

[pittux@PitTuxBox ~]$ sudo rm -f ~/.cache/plasma*
Passwort: 
rm: das Entfernen von '/home/pittux/.cache/plasmashell' ist nicht möglich: Ist ein Verzeichnis
[pittux@PitTuxBox ~]$ plasmashell                
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/pittux/.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/pittux/.local/share/mime", "/usr/share/mime")
No metadata file in the package, expected it at: "/home/pittux/.local/share/"
No metadata file in the package, expected it at: "/home/pittux/.local/share/"
No metadata file in the package, expected it at: "/home/pittux/.local/share/"
No metadata file in the package, expected it at: "/home/pittux/.local/share/"
Couldn't find node translucent-notes. Skipping rendering.
No metadata file in the package, expected it at: "/run/media/pittux/Daten1/Bilder/"
No metadata file in the package, expected it at: "/run/media/pittux/Daten1/Bilder/"
No metadata file in the package, expected it at: "/run/media/pittux/Daten1/Bilder/"
file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Panel.qml:83: TypeError: Cannot read property 'Layout' of null
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
file:///usr/lib/qt5/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/lib/qt5/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/lib/qt5/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/lib/qt5/qml/QtQuick/Controls/Button.qml:100: TypeError: Cannot read property of null
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/main.qml:78:27: Unable to assign [undefined] to QStringList
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/main.qml:37: TypeError: Cannot read property 'DateTime' of undefined
Loading Calendar plugin HolidaysEventsPlugin(0x31c3a40)
KActivities: Database connection:  "kactivities_db_resources_140005357717632_readonly" 
    query_only:          QVariant(qlonglong, 1) 
    journal_mode:        QVariant(QString, "wal") 
    wal_autocheckpoint:  QVariant(qlonglong, 100) 
    synchronous:         QVariant(qlonglong, 0)
link XMLID_10_ hasn't been detected!
Could not resolve property : XMLID_29_
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:443:5: QML Text: Cannot anchor to a null item.
file:///usr/share/plasma/plasmoids/org.kde.plasma.digitalclock/contents/ui/DigitalClock.qml:443:5: QML Text: Binding loop detected for property "height"
Notifications service registered
libkcups: Create-Printer-Subscriptions last error: 0 successful-ok
libkcups: Get-Jobs last error: 0 successful-ok
libkcups: Get-Jobs last error: 0 successful-ok
Plasma Shell startup completed
libkcups: 0
libkcups: 114
KCrash: Attempting to start /usr/bin/plasmashell from kdeinit
sock_file=/run/user/1000/kdeinit5__0
KCrash: Application 'plasmashell' crashing...
KCrash: Attempting to start /usr/lib/drkonqi from kdeinit
sock_file=/run/user/1000/kdeinit5__0
QSocketNotifier: Invalid socket 8 and type 'Read', disabling...
QSocketNotifier: Invalid socket 27 and type 'Read', disabling...

[1]+  Angehalten              plasmashell
[pittux@PitTuxBox ~]$ Unable to start Dr. Konqi
Re-raising signal for core dump handling.

@pittux
Don't mix 2 issues, keep your questions regarding your scanner in your added thread, and give the info that was asked for there.
Also, please use code tags when you post cli output (either select code from the edit menu or use 3 backticks ``` to enclose code, done for you this time.

Did you try to create a new user to see if it is the settings that causes your plasma crashes? systemsettings > Account details > User accounts, and add a new user there, logout and login as that new user. If that fixes your issues, then you have conflicting plasmoids/themes/configurationsin your /home/<username> directory.

I suspected the error through the installation attempt when setting up the scanner driver. Sorry, but I have very little programming knowledge.
Setting up a new user does not work under System Settings / UserContact Details. There is only KWallet.
I can' open User Accounts???

OK, older install, add user-kcm to your system:

sudo pacman -Syu
sudo pacman -S user-kcm

now you will have the option in systemsettings.

I have do it and plasmashell is ok.
how can I repair the user account pittux?

Quickest is to rename ~/.config to something like .config_old (do this when not logged in as that user). Then one by one copy back the settings from that .config_old to the newly created ~/.config (plasma will create it for you), checking each time if plasma still works by logging in..
Or start by removing all plasmoids you added, only use the breeze or midna theme/icons/window-decoration/colors/splash screen. And rename one file at the time until you find which one has the faulty settings. Start with renaming ~/.config/plasma-org.kde.plasma.desktop-appletsrc (again, when logged out) and let plasma recreate that file.

the directory doesn't have executable permission... ("/home/pittux/.local/share/mime"

sudo rm -r ~/.local/share/mime
sudo rm -f ~/.config/plasma*

Plain removing those in ~/.config means losing all settings, again, as stated earlier, rename if you want to be able to keep some of your settings.

Hmm, think about eMail config and browser to copy is enough.