no session created in vncviewer

This issue may be caused by X environment setup on server side

1. check log file:
cat /home/oracle/.vnc/westoracle:1.log

Found below error:

error opening security policy file /usr/lib64/xserver/SecurityPolicy
/home/oracle/.vnc/xstartup: line 9: xsetroot: command not found
/home/oracle/.vnc/xstartup: line 11: xterm: command not found
/home/oracle/.vnc/xstartup: line 12: twm: command not found
Could not init font path element unix/:7100, removing from list!


the problem is missing of xsetroot xterm twm command.

2. install the missing command:

yum install xorg-x11-server-utils-7.1-4.fc6.x86_64 for xsetroot
yum install xterm-215-8.el5_4.1.x86_64 for xterm
yum install xorg-x11-twm-1.0.1-3.1.x86_64 for twm

3. restart vncserver

you should have opened session in vncviewer


reference:
http://www.linuxquestions.org/questions/linux-newbie-8/starting-gnome-session-over-vnc-268828/
http://www.linuxquestions.org/questions/linux-newbie-8/centos-5-3-vnc-problems-802176/
https://forums.oracle.com/forums/thread.jspa?threadID=870033
http://www.linuxquestions.org/questions/fedora-35/could-not-init-font-path-element-unix-7100-removing-from-list-156348/