This bug was originally marked as duplicate of bug 198719, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.

Build: NetBeans IDE 7.0.1 RC1 (Build 201106222100)
VM: Java HotSpot(TM) Client VM, 1.6.0-b105, Java(TM) SE Runtime Environment, 1.6.0-b105
OS: Windows Vista

User Comments:
revathskumar: Happened when closing a document

GUEST: This pops up most of the time especially when i run the project..

GUEST: deploying web module

mrabbah: editing file Article.groovy

GUEST: i opened one of my classes and then when i closed it, this exception appeared.
NOTE : This project had some stuffs not resolved!

GUEST: I was just writing code in the IDE...

vincentliu: Closing a Java Class file

iggylike: Tools->options->formatting -> on and then off line wrap after words for a large file

GUEST: opening dcm4che-soundex.src.main.java.org.dcm4che2.soundex.KPhonetik.java
posibly with wrong (?) codepage windows 1252 (?)

GUEST: Highlighted some data in an editor tabbed window, used the context menu to copy it then closed the tabbed window.  Exception was then displayed.

vincentliu: Closing a Java Class File located in a package.

GUEST: -------------------------------------------------------------------------------
>Log Session: Wednesday, April 27, 2011 9:29:00 AM SGT
>System Info: 
  Product Version         = NetBeans IDE 7.0 (Build 201104080000) (#a693229ccdbb)
  Operating System        = Windows XP version 5.1 running on x86
  Java; VM; Vendor        = 1.6.0-rc; Java HotSpot(TM) Client VM 1.6.0-rc-b101; Sun Microsystems Inc.
  Runtime                 = Java(TM) SE Runtime Environment 1.6.0-rc-b101
  Java Home               = C:\Program Files\Java\jdk1.6.0\jre
  System Locale; Encoding = en_US (nb); Cp1252
  Home Directory          = C:\Documents and Settings\c-laptop
  Current Directory       = C:\Documents and Settings\c-laptop
  User Directory          = C:\Documents and Settings\c-laptop\.netbeans\7.0
  Installation            = C:\Program Files\netbeans\nb
                            C:\Program Files\netbeans\ergonomics
                            C:\Program Files\netbeans\ide
                            C:\Pr

iggylike: Closing the tab by click on the close tab icon

GUEST: Closing the tab where I was editing the code of a class

GUEST: opened netbeans

GUEST: -------------------------------------------------------------------------------
>Log Session: Tuesday, April 12, 2011 12:38:03 PM IST
>System Info: 
  Product Version         = NetBeans IDE 7.0 RC2 (Build 201104070802) (#04aa9273784e)
  Operating System        = Windows XP version 5.1 running on x86
  Java; VM; Vendor        = 1.6.0; Java HotSpot(TM) Client VM 1.6.0-b105; Sun Microsystems Inc.
  Runtime                 = Java(TM) SE Runtime Environment 1.6.0-b105
  Java Home               = C:\Program Files\Java\jdk1.6.0\jre
  System Locale; Encoding = en_US (nb); Cp1252
  Home Directory          = C:\Documents and Settings\Administrator
  Current Directory       = C:\Program Files\NetBeans 7.0 RC2
  User Directory          = C:\Documents and Settings\Administrator\.netbeans\7.0rc2
  Installation            = C:\Program Files\NetBeans 7.0 RC2\nb
                            C:\Program Files\NetBeans 7.0 RC2\ide
                            C:\Program Files\NetBeans 7.0 RC2\websvccommon

revathskumar: Happened when closing a document

GUEST: running a code

GUEST: Reading a file of a Maven-Project

GUEST: Clean and build my projects.

mrabbah: strting netbeans

GUEST: I just Ran my project....

GUEST: ???? ??NullPointerException

revathskumar: On closing a file

iggylike: Closing the tab by cthl-w

GUEST: I dont know when it came, but i saw it after i ran my project.

GUEST: pressed "ctrl" + close tab




Stacktrace: 
java.lang.NullPointerException
   at org.netbeans.modules.editor.lib2.view.DocumentView.checkFontRenderContext(DocumentView.java:651)
   at org.netbeans.modules.editor.lib2.view.DocumentView.checkViewsInited(DocumentView.java:629)
   at org.netbeans.modules.editor.lib2.view.DocumentView.modelToViewChecked(DocumentView.java:1049)
   at org.netbeans.modules.editor.lib2.view.EditorView.modelToView(EditorView.java:253)
   at javax.swing.plaf.basic.BasicTextUI$RootView.modelToView(BasicTextUI.java:1496)
   at javax.swing.plaf.basic.BasicTextUI.modelToView(BasicTextUI.java:1034)