Arch Linux

Open systemsettings -> input devices -> touchpad .
There are no settings (see screenshot)

Log in terminal:

QCoreApplication::arguments: Please instantiate the QApplication object first
kf5.kservice.sycoca: Parse error in "/home/mthw/.config/menus/applications-merged/xdg-desktop-menu-dummy.menu" , line 1 , col 1 : "unexpected end of file"
kf5.kservice.services: The desktop entry file "/usr/share/applications/org.kde.systemmonitor.desktop" has Type= "Application" but no Exec line
kf5.kservice.sycoca: Invalid Service : "/usr/share/applications/org.kde.systemmonitor.desktop"
kf5.kservice.services: The desktop entry file "/usr/share/applications/org.kde.drkonqi.desktop" has Type= "Application" but no Exec line
kf5.kservice.sycoca: Invalid Service : "/usr/share/applications/org.kde.drkonqi.desktop"
kf5.kservice.services: The desktop entry file "/usr/local/share/applications/org.kde.systemmonitor.desktop" has Type= "Application" but no Exec line
kf5.kservice.sycoca: Invalid Service : "/usr/local/share/applications/org.kde.systemmonitor.desktop"
org.kde.systemsettings.app: "View load error: Cannot load library /usr/lib/qt/plugins/classic_mode.so: (libKF5KHtml.so.5: cannot open shared object file: No such file or directory)"
WARNING: viewBackgroundColor is deprecated, use backgroundColor with colorSet: Theme.View instead
WARNING: viewBackgroundColor is deprecated, use backgroundColor with colorSet: Theme.View instead
KActivities: Database connection: "kactivities_db_resources_139971987298368_readonly"
query_only: QVariant(qlonglong, 1)
journal_mode: QVariant(QString, "wal")
wal_autocheckpoint: QVariant(qlonglong, 100)
synchronous: QVariant(qlonglong, 0)
Nothing to load - the client id is empty
Nothing to load - the client id is empty
org.kde.kcoreaddons: Error loading plugin "kded_touchpad" "The shared library was not found."
Plugin search paths are ("/usr/lib/qt/plugins", "/usr/local/bin")
The environment variable QT_PLUGIN_PATH might be not correctly set
Error loading plugin: "The shared library was not found."