Am running drools 5.0.1 ga using the drools/jboss standalone package. When I run the analysis from within guvnor, no error comes up in guvnor and it happily lists the models and attribs, but the following comes up in the server output: 15:06:15,122 ERROR [STDERR] org.drools.RuntimeDroolsException: org.drools.verifier.opposites.Rule_Opposite_LiteralRestrictions_0Eval1Invoker@90c73ecd: java.util.zip.DataFormatException: Value types did not match. Value type boolean was compared to boolean 15:06:15,123 ERROR [STDERR] at org.drools.rule.EvalCondition.isAllowed(EvalCondition.java:122) 15:06:15,123 ERROR [STDERR] The rules all fire as expected, the scenarios all execute, and the rules file (in guvnor) all validates OK. Am a complete java noob, so do not know if it is just something obvious I have missed about boolean defintions? Also, when the "run all scenarios" is run from within guvnor, scenarios are not updated in the same way as when the scenario is run individually. eg I ran the tests individually when setting up, and subsequently only ran all scenarios in batch. Only found out when I ran an xlst on the scenarios to show off how cool this stuff is to the managers, showing last run and last results. Phil