ibus запущен? Попробуйте из терминала запустить и посмотрите вывод в терминале. Я проверял на обновлённом Школьном Мастере 7.0 – родном брате KDesktop.
[sergey@sergey-nout ~]$ ibus-setup
(main.py:5311): Gdk-CRITICAL **: gdk_device_ungrab: assertion 'GDK_IS_DEVICE (device)' failed
(main.py:5311): Gtk-CRITICAL **: gtk_device_grab_remove: assertion 'GDK_IS_DEVICE (device)' failed
(main.py:5311): Gdk-CRITICAL **: gdk_device_ungrab: assertion 'GDK_IS_DEVICE (device)' failed
(main.py:5311): Gtk-CRITICAL **: gtk_device_grab_remove: assertion 'GDK_IS_DEVICE (device)' failed
(main.py:5311): Gdk-CRITICAL **: gdk_device_ungrab: assertion 'GDK_IS_DEVICE (device)' failed
(main.py:5311): Gtk-CRITICAL **: gtk_device_grab_remove: assertion 'GDK_IS_DEVICE (device)' failed
(main.py:5311): Gdk-CRITICAL **: gdk_device_ungrab: assertion 'GDK_IS_DEVICE (device)' failed
(main.py:5311): Gtk-CRITICAL **: gtk_device_grab_remove: assertion 'GDK_IS_DEVICE (device)' failed