Edson - build2589-rev25264-20090214-0603 is the snapshot that I downloaded and installed. However, I have done a search on the source and have not been able to locate MiscTest.testPropertyChangeSupportNewAPI() in the source at all. Interestingly, the DRL compilation does not crash if I use @propertyChangeSupport() or @propertyChangeSupport(true) etc. But otherwise it crashes. It dies in the following code: public DecisionEngine() { super(); try { rulesEngine = new RulesEngine("GlucoseDroolRules00.drl"); //rulesEngine = new RulesEngine("rules_version1.drl"); //rulesEngine = new RulesEngine(); } catch (RulesEngineException e) { System.out.println("Error in DecisionEngine constructor"); e.printStackTrace(); } } public RulesEngine(String rulesFile) throws RulesEngineException { super(); try { readDRLintoPackage(rulesFile); addSpreadsheetToPackage(); } catch (Exception e) { System.out.println(e); throw new RulesEngineException("Could not load/compile rules file: " + rulesFile, e); } } java.lang.NullPointerException Error in DecisionEngine constructor drools.engine.RulesEngineException: Could not load/compile rules file: GlucoseDroolRules00.drl at drools.engine.RulesEngine.<init>(RulesEngine.java:33) at drools.engine.DecisionEngine.<init>(DecisionEngine.java:22) at glucose.tests.AllDroolsRulesTests.setUp(AllDroolsRulesTests.java:33) 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 .junit .internal .runners.BeforeAndAfterRunner.invokeMethod(BeforeAndAfterRunner.java:74) at org .junit .internal .runners.BeforeAndAfterRunner.runBefores(BeforeAndAfterRunner.java:50) at org .junit .internal .runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:33) at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52) at org .eclipse .jdt .internal .junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:45) at org .eclipse .jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org .eclipse .jdt .internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java: 460) at org .eclipse .jdt .internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java: 673) at org .eclipse .jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java: 386) at org .eclipse .jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java: 196) Caused by: java.lang.NullPointerException at org.drools.common.AbstractRuleBase.addPackages(AbstractRuleBase.java: 429) at org.drools.reteoo.ReteooRuleBase.addPackage(ReteooRuleBase.java:394) at drools.engine.RulesEngine.readDRLintoPackage(RulesEngine.java:54) at drools.engine.RulesEngine.<init>(RulesEngine.java:29) ... 16 more If I do put () after the annotation, the DRL file does compile, but I do NOT get dynamic behavior. Thanks. - Mike Can you provide the error messages your are getting? Make sure you use at least build #2589, that include the changes. https://hudson.jboss.org/hudson/job/drools/2589/artifact/trunk/target/ There is a test case for this on MiscTest.testPropertyChangeSupportNewAPI(). []s Edson