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I logged into a Linux server (RHEL) from an linux desktop. There is not any error message at login, but I failed to launch firefox and see the following error emessage:

[myname@myserver ~]$ firefox &
[1] 8806
[myname@myserver ~]$ X11 connection rejected because of wrong authentication.
X11 connection rejected because of wrong authentication.
The application 'firefox' lost its connection to the display localhost:11.0;
most likely the X server was shut down or you killed/destroyed
the application.

I tried to run the following command

[myname@myserver ~]$ xhost +

but get the following error message:

X11 connection rejected because of wrong authentication.
X connection to localhost:11.0 broken (explicit kill or server shutdown).

I also tried to run

[myname@myserver ~]$ echo $DISPLAY

and got the following result


I tried to search this problem from SO but I had no luck. What is the problem and how can I make the firefox work? It seems that the X window cannot be opened.

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migrated from stackoverflow.com Mar 4 '12 at 10:08

This question came from our site for professional and enthusiast programmers.

Has the machines ssh-keys been regenerated after you first connected there? Then you should get a warning message when you connect with ssh from ssh (something along man in the middle warning - host key has changed). – Nils Mar 4 '12 at 20:37

Do not use xhost +. That opens up all sorts of doors and traps.

The best way is to let ssh deal with all of this, so do something like this on your local machine

$ ssh -X remote.machine.net

and once over there, test with a quick

$ xlock &
$ xterm &

which should pop up on your local box. Large apps like firefox take a lot longer.

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Thank you for your comment, but this actually does not work. I logged in using ssh -X -l myname remote.machine.net, but neither xclock nor xterm worked. The error messages are: X11 connection rejected because of wrong authentication. X connection to localhost:10.0 broken (explicit kill or server shutdown). – fanchyna Mar 4 '12 at 3:44
In that case you need to check your ssh configuration. X11 forwarding my be turned off. – Dirk Eddelbuettel Mar 4 '12 at 4:35

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