title: java.lang.InternalError: Can't connect to X11 window server for JVisualVM profiling session
body: <p>I have an Ubuntu server VM (<code>myapp01</code>) and have a Java application deployed there. The app has been acting wonky and I would like to profile it with JVisualVM. To do this I need to install X-Windows on my Windows 7 host, and then get the Ubuntu VM to export its X11 connection to my host when I tell it to run JVisualVM on the VM.</p>
  
  <p>So I started by downloading XMing here:</p>
  
  <pre><code>http://sourceforge.net/projects/xming/files/Xming/6.9.0.31/Xming-6-9-0-31-setup.exe/download
  </code></pre>
  
  <p>I used all default/recommended installation options, including using a normal PuTTy session and allowing public &amp; private network access.  After installing XMing, I launched it and verified it was running on my Windows host.  I then opened up Cygwin and SSHed into the Ubuntu server:</p>
  
  <pre><code>$ ssh myuser@myapp01
  myuser@myapp01's password:
  Welcome to Ubuntu 12.04.4 LTS (GNU/Linux 3.5.0-23-generic x86_64)
  
  * Documentation:  https://help.ubuntu.com/
  
  System information as of Tue Jun 10 21:26:15 EDT 2014
  
  System load:  0.0                Processes:           82
  Usage of /:   22.5% of 11.81GB   Users logged in:     0
  Memory usage: 30%                IP address for eth0: 10.10.41.108
  Swap usage:   0%
  
      Graph this data and manage this system at:
      https://landscape.canonical.com/
  
  38 packages can be updated.
  30 updates are security updates.
  
  Last login: Tue Jun 10 15:03:35 2014 from 10.10.101.96
  </code></pre>
  
  <p>I then export the display to what <em>appears</em> to be my host's IP:</p>
  
  <pre><code>myuser@myapp01:~$ export DISPLAY=10.10.101.96
  </code></pre>
  
  <p>I then attempt to run JVisualVM:</p>
  
  <pre><code>myuser@myapp01:~$ cd $JAVA_HOME
  myuser@myapp01:/usr/lib/jvm/java-7-oracle-amd64$ ls
  bin  COPYRIGHT  db  include  jre  lib  LICENSE  man  README.html  release  src.zip  THIRDPARTYLICENSEREADME-JAVAFX.txt  THIRDPARTYLICENSEREADME.txt
  myuser@myapp01:/usr/lib/jvm/java-7-oracle-amd64$ cd bin/
  myuser@myapp01:/usr/lib/jvm/java-7-oracle-amd64/bin$ ./jvisualvm
  Error: Can't connect to X11 window server using '10.10.101.96' as the value of the DISPLAY variable.
  See the /home/myuser/.visualvm/7u14/var/log/messages.log for details.
  myuser@myapp01:/usr/lib/jvm/java-7-oracle-amd64/bin$ vim /home/myuser/.visualvm/7u14/var/log/messages.log
  </code></pre>
  
  <p>Inside <code>/home/myuser/.visualvm/7u14/var/log/messages.log</code>:</p>
  
  <pre><code>java.lang.InternalError: Can't connect to X11 window server using '10.10.101.96' as the value of the DISPLAY variable.
      at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
      at sun.awt.X11GraphicsEnvironment.access$200(X11GraphicsEnvironment.java:65)
      at sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:110)
      at java.security.AccessController.doPrivileged(Native Method)
      at sun.awt.X11GraphicsEnvironment.&lt;clinit&gt;(X11GraphicsEnvironment.java:74)
      at java.lang.Class.forName0(Native Method)
      at java.lang.Class.forName(Class.java:190)
      at java.awt.GraphicsEnvironment.createGE(GraphicsEnvironment.java:102)
      at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:81)
      at org.netbeans.core.startup.Main.start(Main.java:200)
      at org.netbeans.core.startup.TopThreadGroup.run(TopThreadGroup.java:84)
      at java.lang.Thread.run(Thread.java:745)
  </code></pre>
  
  <p>Ideas? I am VPNed in, could that be affecting anything? Do I have XMing misconfigured somehow? Is my <code>export DISPLAY</code> command wrong?</p>