Hi, all of a sudden this error shows up. So, I upgrade from 4.0.4 to 4.0.7, and the issue is still there. Some posts mention this may be related to the JDT. Do I need to have JDT in my path? Another post said to add the -Ddrools.compiler=JANINO as a Sys prop, which doesn't fix the problem either. Help? -david in Atlanta Code is here: private RuleFactory() { bases = new HashMap(); dsls = new HashMap(); packages = new HashMap(); conf = new PackageBuilderConfiguration(); <----- error happens here /* JavaDialectConfiguration jConf = (JavaDialectConfiguration) conf.getDialectConfiguration( "java" ); jConf.setCompiler( JavaDialectConfiguration.JANINO ); //conf.setJavaLanguageLevel( "1.5" ); conf.setCompiler( PackageBuilderConfiguration. ); */ } And error here: Caused by: java.lang.ExceptionInInitializerError at com.virtuant.mobilitee.helper.DroolsHelper.getWorkingMemory(DroolsHelper.java:57) at com.virtuant.mobilitee.ejb.RuleControllerBean.runPackage(RuleControllerBean.java:395) at com.virtuant.mobilitee.ejb.RuleControllerBean.runPackage(RuleControllerBean.java:361) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) ... 55 more Caused by: org.drools.RuntimeDroolsException: Unable to load dialect 'org.drools.rule.builder.dialect.java.JavaDialectConfiguration:java' at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:160) at org.drools.compiler.PackageBuilderConfiguration.buildDialectConfigurationMap(PackageBuilderConfiguration.java:146) at org.drools.compiler.PackageBuilderConfiguration.init(PackageBuilderConfiguration.java:121) at org.drools.compiler.PackageBuilderConfiguration.(PackageBuilderConfiguration.java:98) at com.virtuant.mobilitee.workflow.RuleFactory.(RuleFactory.java:55) at com.virtuant.mobilitee.workflow.RuleFactory.(RuleFactory.java:44) ... 64 more Caused by: java.lang.ClassCastException: org.drools.rule.builder.dialect.java.JavaDialectConfiguration at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:155) ... 69 more -- View this message in context: http://www.nabble.com/ClassCastException-in-JBoss-4.2.2-tp17494918p174949... Sent from the drools - user mailing list archive at Nabble.com.