[rules-users] could not access property ('=')

Hi. I've currently evaluating Drools 4.0 for a project of ours and I'm running into some problems. I have a rule which looks like this: rule "W250.42 Editable" when DTO(w250_4_1.value in ("0","1","6","7","A","C","D","G","L","M","P","Q","S","V","Z") ) then System.out.println ("0"); Action action = createAction("W250.42", false, true); retList.add(action); end both DTO and w250_4_1 are extremely simple beans. w250_4_1 just has 1 property 'value' which is a String and DTO has one property w250_4_1 which is the bean w250_4_1. Now when I put "0" into w250_4_1 then everything works fine. The rule is true and the 'then' portion is executed. However, if I set w250_4_1 to "6" (which is also present in the in (...)) then I get the following error. org.drools.RuntimeDroolsException: Exception executing predicate org.drools.base.mvel.MVELPredicateExpression@118fa47 at org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:1 97) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:122) at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(Compo siteObjectSinkAdapter.java:317) at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:168) at org.drools.reteoo.Rete.assertObject(Rete.java:168) at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:190) at org.drools.reteoo.ReteooWorkingMemory.doInsert(ReteooWorkingMemory.java: 70) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.jav a:848) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.jav a:822) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.jav a:623) at com.sample.DroolsTest.main(DroolsTest.java:34) Caused by: org.mvel.PropertyAccessException: failed to access property: <<==>> in: class com.sample.DTOShadowProxy at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChai n(ReflectiveAccessorOptimizer.java:137) at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.optimizeAccess or(ReflectiveAccessorOptimizer.java:96) at org.mvel.ASTNode.getReducedValueAccelerated(ASTNode.java:194) at org.mvel.ast.Or.getReducedValueAccelerated(Or.java:18) at org.mvel.MVELRuntime.execute(MVELRuntime.java:87) at org.mvel.CompiledExpression.getValue(CompiledExpression.java:98) at org.mvel.MVEL.executeExpression(MVEL.java:202) at org.drools.base.mvel.MVELPredicateExpression.evaluate(MVELPredicateExpre ssion.java:36) at org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:1 91) ... 10 more Caused by: org.mvel.PropertyAccessException: could not access property ('=') at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.getBeanPropert y(ReflectiveAccessorOptimizer.java:252) at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChai n(ReflectiveAccessorOptimizer.java:106) ... 18 more If I keep w250_4_1 as "0", but move "0" in the rule to any other place place in the in() list (e.g. in ("1","0",...), then I get a similar error. I get similar errors when trying to use 'not in' in the same circumstance, except that then the property is ('!') What seems to be the issue? Thanks in advance! Regards, --Arsalan This message contains information that may be privileged or confidential and is the property of the Capgemini Group. It is intended only for the person to whom it is addressed. If you are not the intended recipient, you are not authorized to read, print, retain, copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message.