vncviewer error:could not connect to session bus :failed to connect to socket/tmp/dbus-XXXXXXXX connection refused

First, I use putty to log in my server computer with vnc4server -geometry 1920x1080. Then I got my port number is 1. The system on my server computer is ubuntu 16.04. Then I use vncviewer to log with 192.168.106.29:1 This is the result:  This is my xstartup file: unset DBUS_SESSION_BUS_ADDRESS [ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup [ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources xsetroot -solid grey vncconfig -iconic & x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" & x-window-manager & mate-session & This is the scw4750:1.log file:

Wed Sep 19 09:33:05 2018

 vncext:      VNC extension running!
 vncext:      Listening for VNC connections on port 5901
 vncext:      created VNC server for screen 0

error opening security policy file /etc/X11/xserver/SecurityPolicy

Could not init font path element /usr/X11R6/lib/X11/fonts/Speedo/, removing from list!

usage: xsetroot [options]
  where options are:
  -display    or   -d 
  -fg    or   -foreground 
  -bg    or   -background 
  -rv   or   -reverse
  -def   or   -default
  -name 
  -cursor  
  -cursor_name 
  -xcf  
  -solid 
  -gray   or   -grey
  -bitmap 
  -mod  
  -help
  -version

mate-session: WARNING: Could not make bus activated clients aware of XDG_CURRENT_DESKTOP=MATE environment variable: Failed to connect to socket /tmp/dbus-X9hRhuXJuM: Connection refused

mate-session: WARNING: Could not make bus activated clients aware of DISPLAY=:1 environment variable: Failed to connect to socket /tmp/dbus-X9hRhuXJuM: Connection refused

mate-session: WARNING: Could not make bus activated clients aware of MATE_DESKTOP_SESSION_ID=this-is-deprecated environment variable: Failed to connect to socket /tmp/dbus-X9hRhuXJuM: Connection refused
mate-session: dconf-WARNING: failed to commit changes to dconf: Could not connect: Connection refused

mate-session: WARNING: Could not make bus activated clients aware of SESSION_MANAGER=local/scw4750:@/tmp/.ICE-unix/3764,unix/scw4750:/tmp/.ICE-unix/3764 environment variable: Failed to connect to socket /tmp/dbus-X9hRhuXJuM: Connection refused

(x-window-manager:3763): xfwm4-WARNING **: The display does not support the XComposite extension.

(x-window-manager:3763): xfwm4-WARNING **: The display does not support the XDamage extension.

(x-window-manager:3763): xfwm4-WARNING **: The display does not support the XFixes extension.

(x-window-manager:3763): xfwm4-WARNING **: Compositing manager disabled.
Failed to parse arguments: Unknown option --login

(x-window-manager:3763): xfwm4-WARNING **: Cannot find visual format on screen 0

(x-window-manager:3763): xfwm4-WARNING **: Failed to connect to session manager: Failed to connect to the session manager: SESSION_MANAGER environment variable not defined
Wed Sep 19 09:36:10 2018
 Connections: accepted: 0.0.0.0::55352
 SConnection: Client needs protocol version 3.8
 SConnection: Client requests security type VncAuth(2)

Wed Sep 19 09:36:14 2018
 Connections: closed: 0.0.0.0::55352 (Clean disconnection)

Wed Sep 19 09:36:19 2018
 Connections: accepted: 0.0.0.0::55357
 SConnection: Client needs protocol version 3.8
 SConnection: Client requests security type VncAuth(2)

Wed Sep 19 09:36:27 2018
 VNCSConnST:  Server default pixel format depth 16 (16bpp) little-endian rgb565
 VNCSConnST:  Client pixel format depth 6 (8bpp) rgb222
 VNCSConnST:  Client pixel format depth 16 (16bpp) little-endian rgb565