Unable to access desktop via VNC

[Trunkzeh]

Creating a bug report/issue

Required Information

• DietPi version | `G_DIETPI_VERSION_CORE=6
  G_DIETPI_VERSION_SUB=25
  G_DIETPI_VERSION_RC=3
  G_GITBRANCH='master'
  G_GITOWNER='MichaIng'
• Distro version | buster
• Kernel version | Linux RPI4 4.19.66-v7l+ DietPi-Config | CPU performance benchmark #1253 SMP Thu Aug 15 12:02:08 BST 2019 armv7l GNU/Linux
• SBC device | RPi 4 Model B (armv7l)
• Power supply used | Official RPI4 USB-C Adapter
• SDcard used | Sandisk Extreme 32GB

Additional Information (if applicable)

• Software title | XFCE & VNC4 / RealVNC
• Was the software title installed freshly or updated/migrated? Fresh 6.25 install & then XFCE VNC4 on first attempt. Then re-install 6.25 and XFCE and RealVNC.
• Can this issue be replicated on a fresh installation of DietPi? Yes.
• Bug report ID | 883d2f7b-94e0-4a7e-90e2-2d7b2bf59b16

Steps to reproduce

1. Install latest version of DietPi
2. Install XFCE desktop
3. Install either VNC4 or RealVNC
4. Dietpi-Autostart wizard will appear; select either Automatic Login (2) or LightDM login mask (16)
5. Restart RPI4.
6. Attempt to connect via VNC viewer on client; VNC will connect however will show 'Cannot currently show the desktop'

Expected behaviour

• VNC session should show local desktop.

Actual behaviour

• VNC session shows 'Cannot currently show the desktop' message on black background.

Extra details

• cat .xsession-errors:

root@RPI4:~# cat .xsession-errors
Xsession: X session started for at Thu 22 Aug 11:38:14 BST 2019
localuser:root being added to access control list
dbus-update-activation-environment: systemd --user not found, ignoring --systemd argument
dbus-update-activation-environment: setting VNCDESKTOP=x11
dbus-update-activation-environment: setting HOSTNAME=RPI4
dbus-update-activation-environment: setting XDG_SESSION_TYPE=x11
dbus-update-activation-environment: setting SHLVL=1
dbus-update-activation-environment: setting HOME=/root
dbus-update-activation-environment: setting DBUS_SESSION_BUS_ADDRESS=unix:path=/tmp/.vnc-0/run/session-75b57e20c88642b3/bus
dbus-update-activation-environment: setting JOURNAL_STREAM=8:15860
dbus-update-activation-environment: setting XDG_SESSION_CLASS=user
dbus-update-activation-environment: setting PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
dbus-update-activation-environment: setting INVOCATION_ID=7f3cb648eff9456db909c839e69d3ada
dbus-update-activation-environment: setting XDG_RUNTIME_DIR=/tmp/.vnc-0/run
dbus-update-activation-environment: setting DISPLAY=:1
dbus-update-activation-environment: setting LANG=en_GB.UTF-8
dbus-update-activation-environment: setting XAUTHORITY=/root/.Xauthority
dbus-update-activation-environment: setting SHELL=/bin/bash
dbus-update-activation-environment: setting DISPLAYNUM=1
dbus-update-activation-environment: setting GPG_AGENT_INFO=/run/user/0/gnupg/S.gpg-agent:0:1
dbus-update-activation-environment: setting PWD=/root
dbus-update-activation-environment: setting XDG_DATA_DIRS=/usr/share/xfce4:/usr/local/share/:/usr/share/
/usr/bin/x-session-manager: X server already running on display :1
xfce4-session: No SSH authentication agent found
gpg-agent[933]: WARNING: "--write-env-file" is an obsolete option - it has no effect
gpg-agent: a gpg-agent is already running - not starting a new one

(xfce4-session:922): xfce4-session-WARNING **: 11:38:15.653: gpg-agent returned no PID in the variables

(xfce4-session:922): xfce4-session-WARNING **: 11:38:15.656: xfsm_manager_load_session: Something wrong with /root/.cache/sessions/xfce4-session-RPI4:1, Does it exist? Permissions issue?
No composite extension

(xfsettingsd:951): xfsettingsd-CRITICAL **: 11:38:15.946: RANDR extension is too old, version 1.1. Display settings won't be applied.

(xfsettingsd:951): xfsettingsd-CRITICAL **: 11:38:15.946: Your XI is too old (1.3) version 1.4 is required.

(xfsettingsd:951): xfsettingsd-CRITICAL **: 11:38:15.952: Failed to change the keyboard repeat

(xfwm4:937): xfwm4-WARNING **: 11:38:16.183: The display does not support the XComposite extension.

(xfwm4:937): xfwm4-WARNING **: 11:38:16.184: Compositing manager disabled.

(xfsettingsd:951): xfsettingsd-WARNING **: 11:38:16.202: Failed to get the _NET_NUMBER_OF_DESKTOPS property.

** (xfdesktop:945): WARNING **: 11:38:16.267: Thumbnailer failed calling GetFlavors

(xfwm4:937): xfwm4-WARNING **: 11:38:16.797: Error opening /dev/dri/card0: No such file or directory

(Thunar:943): dbind-WARNING **: 11:38:17.471: Error retrieving accessibility bus address: org.freedesktop.DBus.Error.ServiceUnknown: The name org.a11y.Bus was not provided by any .service files
xfce4-session: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.
xfwm4: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.
migrate: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.

(xfsettingsd:951): libxfce4ui-WARNING **: 11:41:07.707: ICE I/O Error

(xfsettingsd:951): libxfce4ui-WARNING **: 11:41:07.707: Disconnected from session manager.
xfsettingsd: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.
Gdk-Message: 11:41:07.716: Thunar: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.

xfdesktop: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.

(xfce4-panel:941): libxfce4ui-WARNING **: 11:41:07.740: ICE I/O Error

(xfce4-panel:941): Gtk-CRITICAL **: 11:41:07.740: IA__gtk_main_quit: assertion 'main_loops != NULL' failed
Xsession: X session started for at Thu 22 Aug 11:41:32 BST 2019
localuser:root being added to access control list
dbus-update-activation-environment: systemd --user not found, ignoring --systemd argument
dbus-update-activation-environment: setting VNCDESKTOP=x11
dbus-update-activation-environment: setting HOSTNAME=RPI4
dbus-update-activation-environment: setting XDG_SESSION_TYPE=x11
dbus-update-activation-environment: setting SHLVL=1
dbus-update-activation-environment: setting HOME=/root
dbus-update-activation-environment: setting DBUS_SESSION_BUS_ADDRESS=unix:path=/tmp/.vnc-0/run/session-82f718663e8a47d2/bus
dbus-update-activation-environment: setting JOURNAL_STREAM=8:14204
dbus-update-activation-environment: setting XDG_SESSION_CLASS=user
dbus-update-activation-environment: setting PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
dbus-update-activation-environment: setting INVOCATION_ID=b887fb4c8c0348288ea5223b659d07c6
dbus-update-activation-environment: setting XDG_RUNTIME_DIR=/tmp/.vnc-0/run
dbus-update-activation-environment: setting DISPLAY=:1
dbus-update-activation-environment: setting LANG=en_GB.UTF-8
dbus-update-activation-environment: setting XAUTHORITY=/root/.Xauthority
dbus-update-activation-environment: setting SHELL=/bin/bash
dbus-update-activation-environment: setting DISPLAYNUM=1
dbus-update-activation-environment: setting GPG_AGENT_INFO=/run/user/0/gnupg/S.gpg-agent:0:1
dbus-update-activation-environment: setting PWD=/root
dbus-update-activation-environment: setting XDG_DATA_DIRS=/usr/share/xfce4:/usr/local/share/:/usr/share/
/usr/bin/x-session-manager: X server already running on display :1
xfce4-session: No SSH authentication agent found
gpg-agent[889]: WARNING: "--write-env-file" is an obsolete option - it has no effect
gpg-agent: a gpg-agent is already running - not starting a new one

(xfce4-session:878): xfce4-session-WARNING **: 11:41:33.636: gpg-agent returned no PID in the variables

(xfce4-session:878): xfce4-session-WARNING **: 11:41:33.639: xfsm_manager_load_session: Something wrong with /root/.cache/sessions/xfce4-session-RPI4:1, Does it exist? Permissions issue?
No composite extension

(xfsettingsd:908): xfsettingsd-CRITICAL **: 11:41:33.922: RANDR extension is too old, version 1.1. Display settings won't be applied.

(xfsettingsd:908): xfsettingsd-CRITICAL **: 11:41:33.923: Your XI is too old (1.3) version 1.4 is required.

(xfsettingsd:908): xfsettingsd-CRITICAL **: 11:41:33.931: Failed to change the keyboard repeat

(xfwm4:893): xfwm4-WARNING **: 11:41:34.191: The display does not support the XComposite extension.

(xfwm4:893): xfwm4-WARNING **: 11:41:34.191: Compositing manager disabled.

(xfsettingsd:908): xfsettingsd-WARNING **: 11:41:34.233: Failed to get the _NET_NUMBER_OF_DESKTOPS property.

** (xfdesktop:901): WARNING **: 11:41:34.244: Thumbnailer failed calling GetFlavors

(xfwm4:893): xfwm4-WARNING **: 11:41:34.804: Error opening /dev/dri/card0: No such file or directory

(Thunar:899): dbind-WARNING **: 11:41:35.443: Error retrieving accessibility bus address: org.freedesktop.DBus.Error.ServiceUnknown: The name org.a11y.Bus was not provided by any .service files
xfce4-session: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.
xfwm4: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.

(xfsettingsd:908): libxfce4ui-WARNING **: 11:45:30.669: ICE I/O Error

(xfsettingsd:908): libxfce4ui-WARNING **: 11:45:30.669: Disconnected from session manager.

(xfdesktop:901): libxfce4ui-WARNING **: 11:45:30.670: ICE I/O Error

(xfdesktop:901): libxfce4ui-WARNING **: 11:45:30.671: Disconnected from session manager.
xfsettingsd: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.
xfdesktop: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.
migrate: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.
Gdk-Message: 11:45:30.681: Thunar: Fatal IO error 11 (Resource temporarily unavailable) on X server :1.0.

(xfce4-panel:897): libxfce4ui-WARNING **: 11:45:30.694: ICE I/O Error

(xfce4-panel:897): Gtk-CRITICAL **: 11:45:30.694: IA__gtk_main_quit: assertion 'main_loops != NULL' failed

[Trunkzeh]

Duplicate ticket.