vnc gray screen on debian 10 gnome 3

I describe what I exactly did : First , I installed debian10-netinstall. Then I installed Gnome via 'Tasksel' command. Then I used this Tutorial for installing vnc server. Then I start vncserver via this command tightvncserver -geometry 1024x720 :1 and here is the output : New 'X' desktop is debian:1 Starting applications specified in /home/parsa/.vnc/xstartup Log file is /home/parsa/.vnc/debian:1.log And here is the ~/.vnc/debian:1.log : parsa@debian:~$ tail -f .vnc/debian\:1.log 26/09/19 11:41:12 Xvnc version TightVNC-1.3.9 26/09/19 11:41:12 Copyright (C) 2000-2007 TightVNC Group 26/09/19 11:41:12 Copyright (C) 1999 AT&T Laboratories Cambridge 26/09/19 11:41:12 All Rights Reserved. 26/09/19 11:41:12 See http://www.tightvnc.com/ for information on TightVNC 26/09/19 11:41:12 Desktop name 'X' (debian:1) 26/09/19 11:41:12 Protocol versions supported: 3.3, 3.7, 3.8, 3.7t, 3.8t 26/09/19 11:41:12 Listening for VNC connections on TCP port 5901 # Failed to parse arguments: Unknown option --login As you can see in the last line there is an Error. I fixed that by commenting the line contains "--login" in this file :)) /usr/bin/x-terminal-emulator Then I restarted the vncserver : parsa@debian:~$ tightvncserver -kill :1 Killing Xtightvnc process ID 910 parsa@debian:~$ tightvncserver -geometry 1024x720 :1 New 'X' desktop is debian:1 Starting applications specified in /home/parsa/.vnc/xstartup Log file is /home/parsa/.vnc/debian:1.log Then again lets see the log file tail -f .vnc/debian\:1.log # watch_established: "/org/gnome/desktop/interface/" (establishing: 1) # watch_established: "/org/gnome/settings-daemon/peripherals/mouse/" (establishing: 1) # watch_established: "/org/gnome/desktop/sound/" (establishing: 1) # watch_established: "/org/gnome/desktop/privacy/" (establishing: 1) # watch_established: "/org/gnome/desktop/wm/preferences/" (establishing: 1) # watch_established: "/org/gnome/settings-daemon/plugins/xsettings/" (establishing: 1) # watch_established: "/org/gnome/desktop/a11y/" (establishing: 1) # watch_fast: "/org/gnome/terminal/legacy/" (establishing: 0, active: 0) # unwatch_fast: "/org/gnome/terminal/legacy/" (active: 0, establishing: 1) # watch_established: "/org/gnome/terminal/legacy/" (establishing: 0) Now that the error is gone, I connect to vncserver , and these lines appear in the log : 26/09/19 12:18:05 Got connection from client 192.168.1.131 26/09/19 12:18:05 Using protocol version 3.8 26/09/19 12:18:05 Full-control authentication passed by 192.168.1.131 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 24 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 16 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 22 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 21 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 15 26/09/19 12:18:05 Using zlib encoding for client 192.168.1.131 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding -314 26/09/19 12:18:05 Enabling full-color cursor updates for client 192.168.1.131 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding -223 26/09/19 12:18:05 Pixel format for client 192.168.1.131: 26/09/19 12:18:05 8 bpp, depth 6 26/09/19 12:18:05 true colour: max r 3 g 3 b 3, shift r 4 g 2 b 0 26/09/19 12:18:05 Using raw encoding for client 192.168.1.131 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 24 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 22 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 21 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 16 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 15 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding -314 26/09/19 12:18:05 Enabling full-color cursor updates for client 192.168.1.131 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding -223 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 24 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 16 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 22 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 21 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding 15 26/09/19 12:18:05 Using zlib encoding for client 192.168.1.131 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding -314 26/09/19 12:18:05 Enabling full-color cursor updates for client 192.168.1.131 26/09/19 12:18:05 rfbProcessClientNormalMessage: ignoring unknown encoding -223 26/09/19 12:18:05 Pixel format for client 192.168.1.131: 26/09/19 12:18:05 32 bpp, depth 24, little endian 26/09/19 12:18:05 true colour: max r 255 g 255 b 255, shift r 16 g 8 b 0 26/09/19 12:18:05 no translation needed and I see a gray screen in the vnc viewer with a black X cursor : Could you please help me to fix this problem ? I have googled this rfbProcessClientNormalMessage: ignoring unknown encoding error a lot but I couldn't find a solution. here is my ~/.vnc/xstartup by the way : #!/bin/shxrdb $HOME/.Xresources xsetroot -solid grey x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" & # x-window-manager & gnome-session & Thank you.