I am running weka source in eclipse...
its generating following exception?
--Registering Weka Editors---
Exception in thread "main" java.lang.ExceptionInInitializerError
java.lang.Class.forName0(Native Method)
java.lang.Class.forName(Class.java:186)
weka.core.ClassDiscovery.find(ClassDiscovery.java:344)
weka.gui.GenericPropertiesCreator.generateOutputProperties(GenericPropertiesCreator.java:515)
weka.gui.GenericPropertiesCreator.execute(GenericPropertiesCreator.java:607)
weka.gui.GenericPropertiesCreator.<clinit>(GenericPropertiesCreator.java:150)
weka.core.WekaPackageManager.processGenericPropertiesCreatorProps(WekaPackageManager.java:242)
weka.core.WekaPackageManager.loadPackageDirectory(WekaPackageManager.java:381)
weka.core.WekaPackageManager.loadPackages(WekaPackageManager.java:620)
weka.core.WekaPackageManager.loadPackages(WekaPackageManager.java:580)
weka.gui.GenericObjectEditor.determineClasses(GenericObjectEditor.java:173)
weka.gui.GenericObjectEditor.<clinit>(GenericObjectEditor.java:252)
weka.gui.GUIChooser.<init>(GUIChooser.java:688)
weka.gui.GUIChooser.createSingleton(GUIChooser.java:254)
weka.gui.GUIChooser.main(GUIChooser.java:1507)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:186)
at weka.core.ClassDiscovery.find(ClassDiscovery.java:344)
at weka.gui.GenericPropertiesCreator.generateOutputProperties(GenericPropertiesCreator.java:515)
at weka.gui.GenericPropertiesCreator.execute(GenericPropertiesCreator.java:607)
at weka.gui.GenericPropertiesCreator.<clinit>(GenericPropertiesCreator.java:150)
at weka.core.WekaPackageManager.processGenericPropertiesCreatorProps(WekaPackageManager.java:242)
at weka.core.WekaPackageManager.loadPackageDirectory(WekaPackageManager.java:381)
at weka.core.WekaPackageManager.loadPackages(WekaPackageManager.java:620)
at weka.core.WekaPackageManager.loadPackages(WekaPackageManager.java:580)
at weka.gui.GenericObjectEditor.determineClasses(GenericObjectEditor.java:173)
at weka.gui.GenericObjectEditor.<clinit>(GenericObjectEditor.java:252)
at weka.gui.GUIChooser.<init>(GUIChooser.java:688)
at weka.gui.GUIChooser.createSingleton(GUIChooser.java:254)
at weka.gui.GUIChooser.main(GUIChooser.java:1507)
Caused by: java.lang.NullPointerException
at weka.gui.GenericObjectEditor.getClassnames(GenericObjectEditor.java:1766)
at weka.core.converters.ConverterUtils.initialize(ConverterUtils.java:759)
at weka.core.converters.ConverterUtils.<clinit>(ConverterUtils.java:712)
please help me with this..how to fix this?