This issue was reported manually by mmirilovic.
It already has 73 duplicates 


Build: NetBeans IDE 6.9 RC2 (Build 201005272201)
VM: Java HotSpot(TM) 64-Bit Server VM, 16.3-b01, Java(TM) SE Runtime Environment, 1.6.0_20-b02
OS: Linux

User Comments:
averri: Editing a Scala source code.

GUEST: opening netbeans dev 201005112200 for the 1st time

GUEST: Error occured on startup of netbeans

blackrat: Launching 6.9 beta for the first time, previously installed version 6.7.

GUEST: Starting NetBeans IDE when this error message popped up.

GUEST: opened new JavaFx Application

xylifyx: Expanding packages in the project tree in a maven project

mmirilovic: Imported settings from NB 6.8 and started new RC2 build

GUEST: Creating a project

GUEST: 1) Deinstalled the 'older' 6.8 Netbeans IDE
2) Installed the actual 6.9 Netbeans IDE Dev 201002152000 with all features
3) Started Netbeans IDE
4) Imported old 6.8 Configuration
5) First time, when the error occured
6) Made a new GroovyJavaDemo - Project
7) Compiled and Run --> Second time, when the error occured

GUEST: Error occurs when creating a rails application.

GUEST: Created a new ruby on rails project. When finished, this error appeared.

juanmas07: just open netbeans and start issues. And by pressing the 'View Data' button in left down corner another exception appeard

GUEST: for new install netbeans

GUEST: moving in editor to the begining of line where class definition were

guyost: Occured after I clicked "Clean and Build" on a Web project (that is included in a JavaEE project).

GUEST: first netbeans startup after installation

blackrat: Launching 6.9 beta for the first time... migrating settings from version 6.7

blackrat: Launching 6.9 beta for the first time, previously installed version 6.7.

GUEST: started netbeans

GUEST: waiting for program to open

GUEST: First boot of software. IllegalStateException crashed app.
Restarted computer (WIndows 7) and app booted with exceptions

malakim: Thrown on IDE launch

GUEST: save the options

franci: building a java project

GUEST: Error occured at launch

GUEST: ide

vernon: Access Tools - Options menu

jglick: Restarted IDE with old userdir (with j2seproject open) using a new config=bloated dev build incl. ergonomics.

GUEST: Started netbeans 6.9

toby_net: When first booting NetBeans 6.9beta after importing user data of NetBeans 6.8.

GUEST: Started the IDE




Stacktrace: 
java.lang.NoClassDefFoundError: Could not initialize class org.netbeans.modules.parsing.impl.indexing.errors.ErrorAnnotator
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.doRefresh(TaskCache.java:469)
   at org.netbeans.modules.parsing.impl.indexing.errors.TaskCache.refreshTransaction(TaskCache.java:461)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$Work.index(RepositoryUpdater.java:1604)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSource(RepositoryUpdater.java:3226)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$AbstractRootsWork.scanSources(RepositoryUpdater.java:3126)
   at org.netbeans.modules.parsing.impl.indexing.RepositoryUpdater$RootsWork.getDone(RepositoryUpdater.java:2875)