Пока использую Mate, но "осадок" остался.
Решил возобновить обсуждение.
В .xsession-errors пусто.
В .xsession-errors:0
Running Xsession[5919] Xfce4
/usr/bin/startxfce4: X server already running on display :0
Looking in '/etc/xdg/parcellite/parcelliterc'
Looking in '/etc/xdg/parcellite/parcelliterc'
Flag 0x0001, status 0, EXIT 1 STAT 0
(nm-applet:6111): nm-applet-WARNING **: Error connecting to ModemManager: Ошибка вызова StartServiceByName для org.freedesktop.ModemManager1: GDBus.Error:org.freedesktop.systemd1.LoadFailed: Unit dbus-org.freedesktop.ModemManager1.service failed to load: No such file or directory. See system logs and 'systemctl status dbus-org.freedesktop.ModemManager1.service' for details.
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
kbuildsycoca4 running...
kactivitymanagerd(6079): Couldn't start kglobalaccel from kglobalaccel.desktop: "Не удалось найти службу «kglobalaccel.desktop»."
kactivitymanagerd(6079)/nepomuk (library): Could not find virtuoso to connect to. Aborting