Como corrigir o erro do GDBus e do xlib ao acessar o ambiente GNOME do Ubuntu 16.10 via TightVNC

Question

Gostaria de acessar meu Ubuntu 16.10 VPS usando um ambiente GNOME com VNC, mas ainda estou enfrentando alguns problemas que não consegui resolver até agora. Para instalar e configurar o software, executei os seguintes comandos:

sudo apt-get install ubuntu-gnome-desktop
sudo apt-get install tightvncserver xtightvncviewer tightvnc-java
sudo locale-gen de_DE.UTF-8
sudo apt-get install xfonts-75dpi
sudo apt-get install xfonts-100dpi
sudo apt-get install gnome-panel
sudo apt-get install metacity
sudo apt-get install light-themes
touch ~/.Xresources
vncpasswd

O arquivo ~ / .vnc / xstartup contém inicialmente as seguintes linhas:

#!/bin/sh
xrdb $HOME/.Xresources 
xsetroot -solid grey
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &
# Fix to make GNOME work 
export XKL_XMODMAP_DISABLE=1 
/etc/X11/Xsession

Quando inicio o servidor VNC usando vncserver -geometry 1920x1200 , tudo parece bem de acordo com o arquivo de log em ~ / .vnc

17/02/17 11:47:48 Xvnc version TightVNC-1.3.10
17/02/17 11:47:48 Copyright (C) 2000-2009 TightVNC Group
17/02/17 11:47:48 Copyright (C) 1999 AT&T Laboratories Cambridge
17/02/17 11:47:48 All Rights Reserved.
17/02/17 11:47:48 See http://www.tightvnc.com/ for information on TightVNC
17/02/17 11:47:48 Desktop name 'X' (host:1)
17/02/17 11:47:48 Protocol versions supported: 3.3, 3.7, 3.8, 3.7t, 3.8t
17/02/17 11:47:48 Listening for VNC connections on TCP port 5901
17/02/17 11:47:48 Listening for HTTP connections on TCP port 5801

Eu posso conectar com sucesso do meu PC Windows via VNCViewer e ver uma janela cinza.

Agora, o que não está claro para mim é o que eu tenho que mudar em ~ / .vnc / xstartup para fazer o Gnome rodar. Eu tentei muitas configurações diferentes.

Por exemplo quando mudo xstartup para

#!/bin/sh

xrdb $HOME/.Xresources
xsetroot -solid grey
x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
x-window-manager &

# Fix to make GNOME work
export XKL_XMODMAP_DISABLE=1
/etc/X11/Xsession

#gnome-session &
gnome-panel &
gnome-settings-daemon &
metacity &
nautilus &

e conectar via VNC, recebo as seguintes mensagens de erro no arquivo de log vnc:

17/02/17 14:13:09 Xvnc version TightVNC-1.3.10
17/02/17 14:13:09 Copyright (C) 2000-2009 TightVNC Group
17/02/17 14:13:09 Copyright (C) 1999 AT&T Laboratories Cambridge
17/02/17 14:13:09 All Rights Reserved.
17/02/17 14:13:09 See http://www.tightvnc.com/ for information on TightVNC
17/02/17 14:13:09 Desktop name 'X' (host:1)
17/02/17 14:13:09 Protocol versions supported: 3.3, 3.7, 3.8, 3.7t, 3.8t
17/02/17 14:13:09 Listening for VNC connections on TCP port 5901
17/02/17 14:13:09 Listening for HTTP connections on TCP port 5801
17/02/17 14:13:09   URL http://5801

(nautilus:7807): Gtk-WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files
metacity-Message: could not find XKB extension.
Window manager warning: Missing composite extension required for compositing

(gnome-settings-daemon:7805): rfkill-plugin-WARNING **: Could not open RFKILL control device, please verify your installation

** (gnome-panel:7804): WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files

(nautilus:7807): Gtk-WARNING **: Theme parsing error: <broken file>:1:0: Failed to import: The resource at '/org/gnome/libgd/tagged-entry/default.css' does not exist
Xlib:  extension "XInputExtension" missing on display ":1".
Xlib:  extension "XInputExtension" missing on display ":1".
Xlib:  extension "XInputExtension" missing on display ":1".
Xlib:  extension "XInputExtension" missing on display ":1".
Xlib:  extension "XInputExtension" missing on display ":1".
Xlib:  extension "XInputExtension" missing on display ":1".

(gnome-settings-daemon:7805): media-keys-plugin-WARNING **: Unable to inhibit keypresses: GDBus.Error:org.freedesktop.DBus.Error.AccessDenied: Permission denied

** (gnome-settings-daemon:7805): WARNING **: Unable to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files

** (process:7845): WARNING **: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files

(gnome-settings-daemon:7805): GLib-GIO-CRITICAL **: g_task_return_error: assertion 'error != NULL' failed
Xlib:  extension "XInputExtension" missing on display ":1".
Xlib:  extension "XInputExtension" missing on display ":1".

(gnome-settings-daemon:7805): sharing-plugin-WARNING **: Failed to StopUnit service: GDBus.Error:org.freedesktop.systemd1.NoSuchUnit: Unit rygel.service not loaded.
Xlib:  extension "XInputExtension" missing on display ":1".

(gnome-panel:7804): Gtk-WARNING **: Allocating size to PanelToplevel 0x55e8b9e1fba0 without calling gtk_widget_get_preferred_width/height(). How does the code know the size to allocate?
Xlib:  extension "XInputExtension" missing on display ":1".
Nautilus-Share-Message: Called "net usershare info" but it failed: Failed to execute child process "net" (No such file or directory)
Xlib:  extension "XInputExtension" missing on display ":1".

E isso é o que eu posso ver com o VNCViewer:

Até agora, não consegui corrigir os problemas no arquivo de log. Muito obrigado pela sua ajuda.