[x11] Error: cannot open display: localhost:0.0 - trying to open Firefox from CentOS 6.2 64bit and display on Win7

I am on a Windows7 machine and I'm trying to get firefox to open on the centOS machine, but be displayed on my current screen. When typing firefox in terminal, I am getting the following error:

Error: cannot open display: localhost:0.0

To setup the display I used the command

$ export DISPLAY=localhost:0.0

Some site suggested using the following, but it didn't work either:

$ export DISPLAY=:0.0

I am using PuTTY and I have the Enable X11 forwarding check box checked and XMing is running on Windows. Additionally, the sshd_config on centOS file seems to be setup properly as well:

$ cat /etc/ssh/sshd_config |grep -i x11
#X11Forwarding no
X11Forwarding yes
#X11DisplayOffset 10
X11UseLocalhost yes

I've looked over numerous pages and searched StackOverflow as well, but none have managed to help me in any way. Thank you in advance.

before start make sure of installation:

yum install -y xorg-x11-server-Xorg xorg-x11-xauth xorg-x11-apps

1. start xming or cygwin
2. make connection with X11 forwarding (in putty don't forget to set localhost:0.0 for X display location)
3. edit sshd.cong and restart

     cat /etc/ssh/sshd_config | grep X
                             X11Forwarding yes
                             X11DisplayOffset 10
AddressFamily inet

4. Without the X11 forwarding, you are subjected to the X11 SECURITY and then you must: authorize the remote server to make a connection with the local X Server using a method (for instance, the xhost command) set the display environment variable to redirect the output to the X server of your local computer. In this example: 192.168.2.223 is the IP of the server 192.168.2.2 is the IP of the local computer where the x server is installed. localhost can also be used.

blablaco@blablaco01 ~
$ xhost 192.168.2.223
192.168.2.223 being added to access control list

blablaco@blablaco01 ~
$ ssh -l root 192.168.2.223
[email protected] password:
Last login: Sat May 22 18:59:04 2010 from etcetc
[root@oel5u5 ~]# export DISPLAY=192.168.2.2:0.0
[root@oel5u5 ~]# echo $DISPLAY
192.168.2.2:0.0
[root@oel5u5 ~]# xclock&

Then the xclock application must launch.

Check it on putty or mobaxterm and don't check in remote desktop Manager software. Be careful for user that sudo in.

I faced this issue once and was able to resolve it by fixing of my /etc/hosts. It just was unable to resolve localhost name... Details are here: http://itvictories.com/node/6

In fact, there is 99% that error related to /etc/hosts file

X server just unable to resolve localhost and all consequent actions just fails.

Please be sure that you have a record like

127.0.0.1 localhost

in your /etc/hosts file.

I had this error message:

Error: Can't open display: localhost:13.0

This fixed it for me:

export DISPLAY="localhost:10.0"

You can use this too:

export DISPLAY="127.0.0.1:10.0"

In my case the issue was caused due to mismatch in .Xauthority file. Which initially showed up with "Invalid MIT-MAGIC-COOKIE-1" error and then "Error: cannot open display: :0.0" afterwards

Regenerating the .Xauthorityfile from the user under which I am running the vncserver and resetting the password with a restart of the vnc service and dbus service fixed the issue for me.