Created attachment 100840 [details]
stacktrace

Created attachment 101055 [details]
stacktrace

Created attachment 101769 [details]
stacktrace

remove some part of text, try to remove more

Created attachment 102282 [details]
stacktrace

Invoking "change method parameters"

Occurred after I tried to report an unrelated exception which was a recurrent NPE during editor repaint.

Created attachment 103654 [details]
stacktrace

Changed the min project using set as main project.

Created attachment 105318 [details]
stacktrace

Created attachment 106408 [details]
stacktrace

after closing the project setup dialog.

Created attachment 106473 [details]
stacktrace

This bug already has 100 duplicates 
see http://statistics.netbeans.org/exceptions/detail.do?id=170473

java.lang.NullPointerException
	at javax.swing.text.html.StyleSheet.getRule(StyleSheet.java:210)
	at javax.swing.text.html.StyleSheet$ViewAttributeSet.<init>(StyleSheet.java:2676)
	at javax.swing.text.html.StyleSheet.getViewAttributes(StyleSheet.java:330)
	at javax.swing.text.html.BlockView.setPropertiesFromAttributes(BlockView.java:387)
	at javax.swing.text.html.BlockView.setParent(BlockView.java:57)
	at javax.swing.plaf.basic.BasicTextUI$RootView.setView(BasicTextUI.java:1316)
	at javax.swing.plaf.basic.BasicTextUI.setView(BasicTextUI.java:678)
	at javax.swing.plaf.basic.BasicTextUI.modelChanged(BasicTextUI.java:667)
	at javax.swing.plaf.basic.BasicTextUI$UpdateHandler.propertyChange(BasicTextUI.java:1792)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
	at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
	at java.awt.Component.firePropertyChange(Component.java:8128)
	at javax.swing.text.JTextComponent.setEditable(JTextComponent.java:1781)
	at org.netbeans.modules.uihandler.Installer$SubmitInteractive$1.run(Installer.java:1959)

is the the root cause stacktrace for exc.report problem. It seems to me like JDK bug, really do not know what might be wrong on

browser.setEditable(false);

where 

browser = new JEditorPane();

Will take a look anyway.

JDK problem from my point of view .. similar issue 194458

Based on time when this exception started to appear, i took a look and do not see any possible related change in 
/org/netbeans/modules/uihandler/Connecting.html (which is valid)
 nor in
org.netbeans.modules.uihandler.Installer.java

Reported to JDK team as 7030206.

Closing on our side while waiting for evaluation of the JDK bug report.

The JDK bug was closed with a comment about threading issue on our side - "The fact that the exception is sporadically thrown indicates a threading problem. Please make sure that the provided code is run on the Event Dispatching Thread (see SwingUtilities.isEventDispatchThread())." And if we are sure the problem is not in our code, we should provide a standalone test without NetBeans, our provide more information. See what we provided so far at
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7030206

Reassigning back to the module for evaluation.

Created attachment 108724 [details]
stacktrace

In Java (SE) class library project: In right-click context menu on package node in Projects pane, clicked "rename"

(In reply to comment #11)
> 
> is the the root cause stacktrace for exc.report problem. It seems to me like
> JDK bug, really do not know what might be wrong on
> 
> browser.setEditable(false);
> 
> where 
> 
> browser = new JEditorPane();
> 
> Will take a look anyway.

i'm only guessing but JEditorPane needs to render the text as disabled and because it's showing HTML text it uses some sort of CSS to change text color. and there's bug in the HTML text or in the JDK or both.
the problem should be reproducible in a plain swing app using the same HTML text

core-main
205306:c83cee1d3057

Integrated into 'main-golden'
Changeset: http://hg.netbeans.org/main-golden/rev/c83cee1d3057
User: musilt2@netbeans.org
Log: #188677:  IllegalStateException: Dialog was not created correctly