Hi, I have set all the jars file in the classpath, but still m getting the same exception. The exception is caused by : Null pointer exception. I am not able to understand why it is giving me this exception, while in the mailing list I didn't found anybody having this exception, everyone else I found has 'Class Not found Exception'. This is my code snippet : KnowledgeBuilderConfiguration config = KnowledgeBuilderFactory. newKnowledgeBuilderConfiguration(); config.setProperty("drools.dialect.java.compiler", "ECLIPSE"); KnowledgeBuilder kbuilder =KnowledgeBuilderFactory.newKnowledgeBuilder( config ); //KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource( "shopingdiscount.drl"), ResourceType.DRL); This is my exception: Drools config: unable to use the drools.compiler property. Using default. It was set to:0 org.drools.RuntimeDroolsException: Unable to load dialect 'org.drools.rule.builder.dialect.java.JavaDialectConfiguration:jav :org.drools.rule.builder.dialect.java.JavaDialectConfiguration' at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:274) at org.drools.compiler.PackageBuilderConfiguration.buildDialectConfigurationMap(PackageBuilderConfiguration.java:259 at org.drools.compiler.PackageBuilderConfiguration.init(PackageBuilderConfiguration.java:176) at org.drools.compiler.PackageBuilderConfiguration.<init>(PackageBuilderConfiguration.java:153) at org.drools.builder.impl.KnowledgeBuilderProviderImpl.newKnowledgeBuilderConfiguration(KnowledgeBuilderProviderImp .java:17) at org.drools.builder.KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(KnowledgeBuilderFactory.java:57) a . . . . Caused by: java.lang.NullPointerException at org.drools.rule.builder.dialect.java.JavaDialectConfiguration.setCompiler(JavaDialectConfiguration.java:92) at org.drools.rule.builder.dialect.java.JavaDialectConfiguration.init(JavaDialectConfiguration.java:55) at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:270) ... 69 more Am I missing anything that is to initialized , so that I can get through this Null Pointer Exception. Please help me to through of this situation. I am stuck in this. Thanks & Regards Pardeep Ruhil ______________________________________________________________________