X Server error after installing KDE+Vncserver
 

Few days back I configured my coLinux 0.6.3 (Debian Linux 3.1 Kernel 2.6.11) system for using KDE by installing KDE, vncserver on Linux and TightVnc on WinXP SP2.

Now I can use KDE 3.3.2 desktop from WinXP using TightVNC viewer. But this recent installation has affected the X Server in a way that it refuses access to any other client like dpkg-reconfigure, xterm, xlsfonts, etc.

I get following error(s) while trying to execute-

----------------------------------------------------------
root@coLinux:/etc# dpkg-reconfigure xserver-xfree86
Xlib: connection to "10.3.75.2:0.0" refused by server
Xlib: Client is not authorized to connect to Server
dpkg-reconfigure: cannot connect to X server 10.3.75.2:0
----------------------------------------------------------
root@coLinux:/etc# xterm
Xlib: connection to "10.3.75.2:0.0" refused by server
Xlib: Client is not authorized to connect to Server
Warning: This program is an suid-root program or is being run by the root user. The full text of the error or warning message cannot be safely formatted in this environment. You may get a more descriptive message by running the program as a non-root user or by removing the suid bit on the executable. xterm Xt error: Can't open display: %s
----------------------------------------------------------
root@coLinux:/etc# xlsfonts RET
Xlib: connection to "10.3.75.2:0.0" refused by server
Xlib: Client is not authorized to connect to Server
xlsfonts: unable to open display '10.3.75.2:0'
----------------------------------------------------------

Even when trying to install new packages, dpkg-preconfigure gives the same "cannot connect to X server" error.

My configuration:
For coLinux, eth0 is set to 10.3.75.2
In /etc/bash.bashrc, I am exporting DISPLAY as-
export DISPLAY=10.3.75.2:0

I am using kdm as x-window manager.
I have following setup in /etc/kde3/kdm/

Xservers-
#:0 local@tty1 /usr/X11R6/bin/X -nolisten tcp
#:1 local@tty2 reserve /usr/X11R6/bin/X -nolisten tcp :1
#:2 local@tty3 reserve /usr/X11R6/bin/X -nolisten tcp :2
#:3 local@tty4 reserve /usr/X11R6/bin/X -nolisten tcp :3
#:4 local@tty5 reserve /usr/X11R6/bin/X -nolisten tcp :4
:0 local /usr/bin/Xvnc :0 -geometry 1016x704 -depth 32 -desktop vt7

Xaccess-
* #any host can get a login window
* CHOOSER BROADCAST #any indirect host can get a chooser


Before KDE installation, dpkg and other programs were working correctly. What have I done wrong?

Please advise.

Thanks & Regards,
Rad.

It is because by default root does not have access to X. If you want ALL users to be able to launch graphical applications from a command line you can disable X access controls. As a normal user type "xhost +" to disable it. You can type "xhost -" to enable it again but that means that you cannot launch applications as root from the shell. You can also simply add root to the access list although I am unsure of the syntax for that.

*note: those are plus/minus signs in the xhost commands - see "man xhost" for more information.