All, I am in the process of migrating my 3.0. project to the 4.x series and when I attempt to run my code I get the following exception when I attempt to load my .drl files: Caused by: org.drools.RuntimeDroolsException: Unable to load dialect ' org.drools.rule.builder.dialect.java.JavaDialect:java' Here is my package builder code: static { try { builder = new PackageBuilder(); builder.addPackageFromDrl( new InputStreamReader( RtvDecisionEngine.class.getResourceAsStream("rtv.drl" ) ) ); builder.addPackageFromDrl( new InputStreamReader( RtvDecisionEngine.class.getResourceAsStream("modelDiscrepancyRules.drl" ) ) ); ruleBase = RuleBaseFactory.newRuleBase(); ruleBase.addPackage( builder.getPackage() ); } catch(Exception e) { throw new RuntimeException("Failure loading the Rules", e); } } Any thoughts appreciated. Ron