SpringSource STS Install under Linux gives NullPointer / Can't connect to X11 window server using 'localhost:10.0' as the value of the DISPLAY variable.

Run these 2 commands if you get an error like the one shown below:
[user@domain ~]$ chmod 644 .Xauthority 

[user@domain ~]$ export XAUTHORITY=~/.Xauthority 

[user@domain Downloads]$ sudo sh spring-tool-suite-3.0.0.RELEASE-e4.2-linux-gtk-installer.sh

[user@domain Downloads]$ chmod 600 ~/.Xauthority 

Error during install:
[user@domain Downloads]$ ls
spring-tool-suite-3.0.0.RELEASE-e4.2-linux-gtk-installer.sh
[user@domain Downloads]$ sudo sh spring-tool-suite-3.0.0.RELEASE-e4.2-linux-gtk-installer.sh
[sudo] password for user: 

*******************************************************************************
*                               Welcome to the                                *
*                    SpringSource Tool Suite 3.0.0.RELEASE                    *
*                                  Installer                                  *
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 preparing the installer... done
 starting UI installer. please follow instructions on screen...X11 connection rejected because of wrong authentication.
java.lang.NullPointerException
at javax.swing.MultiUIDefaults.getUIError(MultiUIDefaults.java:133)
at javax.swing.UIDefaults.getUI(UIDefaults.java:759)
at javax.swing.UIManager.getUI(UIManager.java:1000)
at javax.swing.JOptionPane.updateUI(JOptionPane.java:1878)
at javax.swing.JOptionPane.<init>(JOptionPane.java:1841)
at javax.swing.JOptionPane.showOptionDialog(JOptionPane.java:859)
at javax.swing.JOptionPane.showMessageDialog(JOptionPane.java:668)
at javax.swing.JOptionPane.showMessageDialog(JOptionPane.java:639)
at com.izforge.izpack.installer.GUIInstaller.showFatalError(GUIInstaller.java:138)
at com.izforge.izpack.installer.GUIInstaller.<init>(GUIInstaller.java:129)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at java.lang.Class.newInstance0(Class.java:372)
at java.lang.Class.newInstance(Class.java:325)
at com.izforge.izpack.installer.Installer.main(Installer.java:118)
Exception in thread "main" java.lang.InternalError: Can't connect to X11 window server using 'localhost:10.0' as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.access$200(X11GraphicsEnvironment.java:62)
at sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:178)
at java.security.AccessController.doPrivileged(Native Method)
at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:142)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:186)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:82)
at sun.swing.SwingUtilities2.isLocalDisplay(SwingUtilities2.java:1393)
at javax.swing.plaf.metal.MetalLookAndFeel.initComponentDefaults(MetalLookAndFeel.java:1563)
at javax.swing.plaf.basic.BasicLookAndFeel.getDefaults(BasicLookAndFeel.java:147)
at javax.swing.plaf.metal.MetalLookAndFeel.getDefaults(MetalLookAndFeel.java:1599)
at javax.swing.UIManager.setLookAndFeel(UIManager.java:530)
at javax.swing.UIManager.setLookAndFeel(UIManager.java:570)
at javax.swing.UIManager.initializeDefaultLAF(UIManager.java:1320)
at javax.swing.UIManager.initialize(UIManager.java:1407)
at javax.swing.UIManager.maybeInitialize(UIManager.java:1395)
at javax.swing.UIManager.getInstalledLookAndFeels(UIManager.java:410)
at javax.swing.UIManager.installLookAndFeel(UIManager.java:453)
at com.incors.plaf.kunststoff.KunststoffLookAndFeel.<init>(KunststoffLookAndFeel.java:58)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at java.lang.Class.newInstance0(Class.java:372)
at java.lang.Class.newInstance(Class.java:325)
at com.izforge.izpack.installer.GUIInstaller.loadLookAndFeel(GUIInstaller.java:532)
at com.izforge.izpack.installer.GUIInstaller.init(GUIInstaller.java:158)
at com.izforge.izpack.installer.GUIInstaller.<init>(GUIInstaller.java:120)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at java.lang.Class.newInstance0(Class.java:372)
at java.lang.Class.newInstance(Class.java:325)
at com.izforge.izpack.installer.Installer.main(Installer.java:118)
 done
 cleaning up... done

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*                         For more information vist:                          *
*                  http://www.springsource.com/products/sts                   *
*******************************************************************************