This exception always occured when I open a project with the ProjectManager and 
a previously opened project already exists. I'm using netbeans 3.2 RC3. 

java 
version "1.3.0_02"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0_02)
Java HotSpot(TM) Client VM (build 1.3.0_02, mixed mode)

Windows NT 4.0 Build 1381 Service Pack 6


Thu Apr 26 10:17:20 GMT+02:00 2001: java.lang.NullPointerException: null
Annotation: Type= 2, name = org.netbeans.modules.java.settings.JavaSettings
java.lang.NullPointerException
        at org.netbeans.modules.java.JavaNode$StateUpdater.propertyChange
(JavaNode.java:875)
        at java.beans.PropertyChangeSupport.firePropertyChange
(PropertyChangeSupport.java:152)
        at org.openide.util.SharedClassObject.firePropertyChange
(SharedClassObject.java:334)
        at org.openide.options.SystemOption.firePropertyChange
(SystemOption.java:82)
        at org.openide.options.SystemOption.readExternal(SystemOption.java:262)
        at org.openide.options.ContextSystemOption.readExternal
(ContextSystemOption.java:111)
        at org.netbeans.modules.java.settings.JavaSettings.readExternal
(JavaSettings.java:463)
        at org.openide.util.SharedClassObject$WriteReplace.readObject
(SharedClassObject.java:475)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.io.ObjectInputStream.invokeObjectReader
(ObjectInputStream.java:2213)
        at java.io.ObjectInputStream.inputObject(ObjectInputStream.java:1410)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:386)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:236)
        at org.netbeans.modules.projects.content.XMLSupport.deserializeValue
(XMLSupport.java:97)
        at org.netbeans.modules.projects.content.XMLSupport.decodeValue
(XMLSupport.java:84)
        at 
org.netbeans.modules.projects.content.XMLProjectContent$XMLSettingsSet.read
(XMLProjectContent.java:610)
        at org.netbeans.modules.projects.PSupport.projectOpen(PSupport.java:247)
        at org.netbeans.core.NbProjectOperation.setProject
(NbProjectOperation.java:129)
        at org.netbeans.core.NbTopManager.openProject(NbTopManager.java:468)
        at org.netbeans.modules.projects.ProjectManagerPanel.openProject
(ProjectManagerPanel.java:337)
        at org.netbeans.modules.projects.ProjectManagerPanel.access$1300
(ProjectManagerPanel.java:38)
        at org.netbeans.modules.projects.ProjectManagerPanel$12.run
(ProjectManagerPanel.java:278)
        at org.openide.util.Task.run(Task.java:124)
[catch] at org.openide.util.RequestProcessor$ProcessorThread.run
(RequestProcessor.java:626)