[CentOS] Xwindow: unable to connect to display in CR 6.8

Tue May 17 01:57:11 UTC 2016
Gilbert Sebenste <sebenste at weather.admin.niu.edu>

On Mon, 16 May 2016, Gilbert Sebenste wrote:

> Hello everyone,
>
> I just installed the CentOS 6.8 updates from the CR repository,
> and then I rebooted the server. I run some software to make weather
> images on a website, and I have run into a problem. When I do it, the
> software, as it tries to plot the image, says:
>
> Xwindow: unable to connect to display
>
> It just stopped working when I did the updates. Has anyone else seen this, or 
> have an idea on what to look for to get this fixed? To plot it, I
> use syntax's of
>
> machine: 0
> machine: 1
> machine: 2
>
> Which lets me plot it using virtual frame buffers (Xvfb). When I do xhost + 
> servername , it says it has been added to the control list...but it still 
> doesn't fix the issue. Does anyone know what I may be doing wrong?

Also, doing an "xhost +" does not help, either, and in 
/etc/gdm/custom.conf, I have:

DisallowTCP=false

Any ideas would be greatly appreciated. Thank you!

Gilbert

*******************************************************************************
Gilbert Sebenste                                                    ********
(My opinions only!)                                                  ******
*******************************************************************************