I did the upgrade of the KDE Neon 18.4 to 20.4.

After the upgrade to KDE NEon 20.04 the login (login-srceen) is slow and I can find error messages from the log.

There was another report about a Qt-issue in the sddm but i am not sure if this has anything to do with the qt as the errors of the sddm-greeter are of type:
"Cannot create children for a parent that is in a different thread"
"Could not add child element to parent element because the types are incorrect."
"file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:39: TypeError: Cannot read property" etc.
How can I fix this ?

I am including the complete grep "sddm" of my journalctl -b below:

Code: Select all

syys 06 19:35:09 TUF-Neon sddm[856]: Initializing...
syys 06 19:35:09 TUF-Neon sddm[856]: Starting...
syys 06 19:35:09 TUF-Neon sddm[856]: Logind interface found
syys 06 19:35:09 TUF-Neon sddm[856]: Adding new display on vt 1 ...
syys 06 19:35:09 TUF-Neon sddm[856]: Loading theme configuration from ""
syys 06 19:35:09 TUF-Neon sddm[856]: Display server starting...
syys 06 19:35:09 TUF-Neon sddm[856]: Running: /usr/bin/X -nolisten tcp -auth /var/run/sddm/{8da82d68-816b-4eb8-8c48-c833b86d9071} -background none -noreset -displayfd 17 -seat seat0 vt1
syys 06 19:35:10 TUF-Neon sddm[856]: Setting default cursor
syys 06 19:35:10 TUF-Neon sddm[856]: Running display setup script  "/usr/share/sddm/scripts/Xsetup"
syys 06 19:35:10 TUF-Neon sddm[856]: Display server started.
syys 06 19:35:10 TUF-Neon sddm[856]: Socket server starting...
syys 06 19:35:10 TUF-Neon sddm[856]: Socket server started.
syys 06 19:35:10 TUF-Neon sddm[856]: Loading theme configuration from "/usr/share/sddm/themes/breeze/theme.conf"
syys 06 19:35:10 TUF-Neon sddm[856]: Greeter starting...
syys 06 19:35:10 TUF-Neon sddm[856]: Adding cookie to "/var/run/sddm/{8da82d68-816b-4eb8-8c48-c833b86d9071}"
syys 06 19:35:10 TUF-Neon sddm-helper[934]: [PAM] Starting...
syys 06 19:35:10 TUF-Neon sddm-helper[934]: [PAM] Authenticating...
syys 06 19:35:10 TUF-Neon sddm-helper[934]: [PAM] returning.
syys 06 19:35:10 TUF-Neon sddm-helper[934]: pam_unix(sddm-greeter:session): session opened for user sddm by (uid=0)
syys 06 19:35:10 TUF-Neon systemd-logind[749]: New session 1 of user sddm.
syys 06 19:35:10 TUF-Neon systemd[943]: pam_unix(systemd-user:session): session opened for user sddm by (uid=0)
syys 06 19:35:10 TUF-Neon systemd[1]: Started Session 1 of user sddm.
syys 06 19:35:10 TUF-Neon sddm[856]: Greeter session started successfully
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: High-DPI autoscaling not Enabled
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: Reading from "/usr/share/xsessions/plasma.desktop"
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: Reading from "/usr/share/wayland-sessions/plasmawayland.desktop"
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: Loading theme configuration from "/usr/share/sddm/themes/breeze/theme.conf"
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: Connected to the daemon.
syys 06 19:35:10 TUF-Neon sddm[856]: Message received from greeter: Connect
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: Loading file:///usr/share/sddm/themes/breeze/Main.qml...
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: QObject: Cannot create children for a parent that is in a different thread.
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: QObject: Cannot create children for a parent that is in a different thread.
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: QObject: Cannot create children for a parent that is in a different thread.
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: QObject: Cannot create children for a parent that is in a different thread.
syys 06 19:35:10 TUF-Neon sddm-greeter[956]: QObject::installEventFilter(): Cannot filter events for objects in a different thread.
syys 06 19:35:10 TUF-Neon dbus-daemon[723]: [system] Activating via systemd: service name='org.freedesktop.UDisks2' unit='udisks2.service' requested by ':1.34' (uid=116 pid=956 comm="/usr/bin/sddm-greeter --socket /tmp/sddm-:0-oaCIxm" label="unconfined")
syys 06 19:35:24 TUF-Neon dbus-daemon[723]: [system] Activating via systemd: service name='org.freedesktop.UPower' unit='upower.service' requested by ':1.34' (uid=116 pid=956 comm="/usr/bin/sddm-greeter --socket /tmp/sddm-:0-oaCIxm" label="unconfined")
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:406:376: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:407:126: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:408:126: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:408:385: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:409:125: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:410:124: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:411:125: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:411:371: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:24 TUF-Neon sddm-greeter[956]: <input>:411:619: Could not add child element to parent element because the types are incorrect.
syys 06 19:35:25 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/plasma/components/Button.qml:52: ReferenceError: PlasmaCore is not defined
syys 06 19:35:25 TUF-Neon sddm-greeter[956]: Adding view for "DVI-D-0" QRect(0,0 1680x1050)
syys 06 19:35:25 TUF-Neon sddm-greeter[956]: QDBusConnection: name 'org.freedesktop.UDisks2' had owner '' but we thought it was ':1.9'
syys 06 19:35:25 TUF-Neon sddm-greeter[956]: Message received from daemon: Capabilities
syys 06 19:35:25 TUF-Neon sddm-greeter[956]: Hunspell dictionary is missing for "en_GB" . Search paths ("/usr/share/qt5/qtvirtualkeyboard/hunspell", "/usr/share/hunspell", "/usr/share/myspell/dicts")
syys 06 19:35:25 TUF-Neon sddm-greeter[956]: Message received from daemon: HostName
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: Reading from "/usr/share/xsessions/plasma.desktop"
syys 06 19:35:30 TUF-Neon sddm[856]: Message received from greeter: Login
syys 06 19:35:30 TUF-Neon sddm[856]: Reading from "/usr/share/xsessions/plasma.desktop"
syys 06 19:35:30 TUF-Neon sddm[856]: Reading from "/usr/share/xsessions/plasma.desktop"
syys 06 19:35:30 TUF-Neon sddm[856]: Session "/usr/share/xsessions/plasma.desktop" selected, command: "/usr/bin/startplasma-x11"
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: [PAM] Starting...
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: [PAM] Authenticating...
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: [PAM] Preparing to converse...
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: [PAM] Conversation with 1 messages
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: pam_kwallet5(sddm:auth): (null): pam_sm_authenticate
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: [PAM] returning.
syys 06 19:35:30 TUF-Neon sddm[856]: Authenticated successfully
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: Message received from daemon: LoginSucceeded
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: pam_kwallet5(sddm:setcred): pam_kwallet5: pam_sm_setcred
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: pam_unix(sddm:session): session opened for user mika by (uid=0)
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/Main.qml:463: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/plasma/workspace/components/BatteryIcon.qml:42: TypeError: Cannot call method 'roundToIconSize' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/Battery.qml:27: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/Main.qml:441: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/Main.qml:446: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/Main.qml:157: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:102: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:39: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:55: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:41: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:42: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:102: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:39: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:55: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:41: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:42: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:102: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:39: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:55: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:41: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:42: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:102: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:39: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:55: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:41: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/ActionButton.qml:42: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/Login.qml:120: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/Login.qml:115: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/SessionManagementScreen.qml:84: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/SessionManagementScreen.qml:114: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/SessionManagementScreen.qml:100: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/SessionManagementScreen.qml:101: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/SessionManagementScreen.qml:91: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserList.qml:25: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserList.qml:26: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:51: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:114: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:49: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:51: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:114: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:49: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:51: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:114: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ToolButtonStyle.qml:49: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ButtonStyle.qml:96: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/ButtonStyle.qml:41: TypeError: Cannot read property 'smallSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/TextFieldStyle.qml:90: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/TextFieldStyle.qml:90: TypeError: Cannot read property 'iconSizes' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:103: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:44: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:78: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:69: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:95: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:103: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:44: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:69: TypeError: Cannot read property 'largeSpacing' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:95: TypeError: Cannot read property 'gridUnit' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:75: TypeError: Cannot read property 'longDuration' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/components/UserDelegate.qml:50: TypeError: Cannot read property 'longDuration' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/QtQuick/Controls/Styles/Plasma/private/TextFieldFocus.qml:93: TypeError: Cannot read property 'longDuration' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/Main.qml:240: TypeError: Cannot read property 'longDuration' of null
syys 06 19:35:30 TUF-Neon sddm-greeter[956]: file:///usr/share/sddm/themes/breeze/Main.qml:468: TypeError: Cannot read property 'longDuration' of null
syys 06 19:35:30 TUF-Neon sddm-helper[934]: [PAM] Closing session
syys 06 19:35:30 TUF-Neon sddm-helper[934]: pam_unix(sddm-greeter:session): session closed for user sddm
syys 06 19:35:30 TUF-Neon sddm-helper[934]: [PAM] Ended.
syys 06 19:35:30 TUF-Neon sddm[856]: Auth: sddm-helper exited successfully
syys 06 19:35:30 TUF-Neon sddm[856]: Greeter stopped.
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: pam_kwallet5(sddm:session): pam_kwallet5: pam_sm_open_session
syys 06 19:35:30 TUF-Neon sddm-helper[1202]: pam_kwallet5: final socket path: /run/user/1001/kwallet5.socket
syys 06 19:35:30 TUF-Neon sddm-helper[1173]: Starting: "/etc/sddm/Xsession \"/usr/bin/startplasma-x11\""
syys 06 19:35:30 TUF-Neon sddm-helper[1204]: Adding cookie to "/home/mika/.Xauthority"
syys 06 19:35:30 TUF-Neon sddm[856]: Session started
syys 06 21:28:31 TUF-Neon sudo[5287]:     mika : TTY=pts/1 ; PWD=/home/mika ; USER=root ; COMMAND=/bin/journalctl -b -u sddm-greeter
syys 06 21:30:22 TUF-Neon sudo[5331]:     mika : TTY=pts/1 ; PWD=/home/mika ; USER=root ; COMMAND=/bin/journalctl -b -u sddm.service
syys 06 21:31:25 TUF-Neon sudo[5338]:     mika : TTY=pts/1 ; PWD=/home/mika ; USER=root ; COMMAND=/bin/journalctl -b -u sddm-greeter


Any advice?

Should I just install another theme for SDDM and disregard the issue ?

To me it looks like something has went wrong in instlling/upgrading the Breeze theme.
I have fairly new KDE Neon 18.4 (user edition) that was upgraded to 20.04 through the prompted suggestion. I do not recall changing the default themes. Now it seems to be Breeze across Plasma.

My issue is not the qt-version issue. I seem to have qt 5.14 installed.

The sddm-theme-breeze seems to be 4:5.19.5-0xneon+20.04+focal+build8
The issue seems to relate sddm-greeter not being able to read some properties from the .qml files in the /usr/share/sddm/themes/breeze/components.

Should I file a bug report somewhere?