System settings is unable to display Look and Feel, Desktop theme, Cursor theme and Welcome screen due to missing files, this is the error output producen when opeing any on the configuration pages: kcmshell5 kcm_lookandfeel Plugin search paths are ("/usr/lib/x86_64-linux-gnu/qt5/plugins", "/usr/bin") The environment variable QT_PLUGIN_PATH might be not correctly set "file:///usr/share/kpackage/kcms/kcm_lookandfeel/contents/ui/main.qml" "Error loading QML file.\n23: module \"org.kde.kirigami\" version 2.4 is not installed\n" It says kirigami 2.4 isn't installed but both qml-module-org-kde-kirigami and qml-module-org-kde-kirigami2 are installed and updated (KDE dev stable update channel)
*** This bug has been marked as a duplicate of bug 387689 ***