mesma coisa no xfce4, mas eu não tive a mesma mensagem de erro:
mais muita mensagem de erro como:
(polkit-gnome-authentication-agent-1:28411): GLib-GObject-CRITICAL **: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
(polkit-gnome-authentication-agent-1:28411): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
(polkit-gnome-authentication-agent-1:28411): Gdk-CRITICAL **: gdk_cairo_surface_create_from_pixbuf: assertion 'GDK_IS_PIXBUF (pixbuf)' failed
(polkit-gnome-authentication-agent-1:28411): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
(polkit-gnome-authentication-agent-1:28411): Gtk-WARNING **: Error loading theme icon 'gtk-cancel' for stock: Unrecognized image file format
(polkit-gnome-authentication-agent-1:28411): Gtk-WARNING **: Error loading theme icon 'image-missing' for stock: L'icône « image-missing » n'est pas présente dans le thème elementary-xfce-dark
(polkit-gnome-authentication-agent-1:28411): GLib-GObject-CRITICAL **: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
(polkit-gnome-authentication-agent-1:28411): Gdk-CRITICAL **: gdk_cairo_surface_create_from_pixbuf: assertion 'GDK_IS_PIXBUF (pixbuf)' failed
(polkit-gnome-authentication-agent-1:28411): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
(polkit-gnome-authentication-agent-1:28411): Gtk-WARNING **: Error loading theme icon 'gtk-cancel' for stock: Unrecognized image file format
(polkit-gnome-authentication-agent-1:28411): Gtk-WARNING **: Error loading theme icon 'image-missing' for stock: L'icône « image-missing » n'est pas présente dans le thème elementary-xfce-dark
(polkit-gnome-authentication-agent-1:28411): GLib-GObject-CRITICAL **: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
(polkit-gnome-authentication-agent-1:28411): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
(polkit-gnome-authentication-agent-1:28411): Gdk-CRITICAL **: gdk_cairo_surface_create_from_pixbuf: assertion 'GDK_IS_PIXBUF (pixbuf)' failed
agora está funcionando apenas adicionando as duas linhas da postagem e alterando o posicionamento para xfce4