ok, I found a workaround: I downgraded xfce4-session from 4.18.1 to 4.18.0. With this, login is working again and the xsession eror does not appear.
ok, I found a workaround: I downgraded xfce4-session from 4.18.1 to 4.18.0. With this, login is working again and the xsession eror does not appear.