This bug was originally marked as duplicate of bug 201589, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE Dev (Build 20110919-27d5a2c669e1)
VM: Java HotSpot(TM) 64-Bit Server VM, 20.1-b02, Java(TM) SE Runtime Environment, 1.6.0_26-b03
ralphbenjamin: Expand the package org.netbeans.modules.refactoring.java.ui with the mouse by dubbleclick'ing.
sunbiz: Added project to favorites and clicked on the expand icon to look inside the folder, got this exception
ttokoly: Expanding nodes in Files window
athompson: added folder to favorites
GUEST: Opening "Source Files" on a new project.
I was opening a package in the Explorer lokking for a Java class.
mago_ebon: I was expanding the lib directory in a Java Application. The project is versioned using SVN.
athompson: opened a folder in the "Files" tab
tnleeuw: Browsing in projects tree
GUEST: Adding a directory to the Ignore path
mkristofic: Expand package node in navigator
asenk: 1. Start IDE with fresh user dir
2. Create new Project-> NetBeans Modules-> Module
4. Type :org.something.name in Code Name Base
tstupka: switch from projects to files view
pjiricka: Expanded nbproject of a web project in the Files view.
ovrabec: expanding build folder of a j2se project in files view
tim_sa: browsing files
javydreamercsw: Opening a node (package) withing a module
javydreamercsw: Opening package
ttokoly: Product Version: NetBeans IDE Dev (Build 201109060600)
Java: 1.7.0; Java HotSpot(TM) Client VM 21.0-b17
System: Windows XP version 5.1 running on x86; Cp1252; en_US (nb)
I've opened several java files (about ten files) and than closed few of them by shortcut ctrl+w and this error occured.
But I think that this is random issue...
rdelaplante: I was scrolling down in the Files tab. I have three facelets template editors open, and one CSS file open.
muellermi: opening folder in project tree
jhavlin: Opened a java package.
ovrabec: expanding a java package in projects view
mklaehn: expand node(package with bundle-files only)
Created attachment 110908 [details]
Integrated into 'main-golden'
User: Jaroslav Tulach <email@example.com>
Log: #202349: Deleting the (no longer used) method, so it cannot lead to AssertionError