Hello there and a happy new year to everyone reading :) Why am I here again? Yep, got a problem. Don't know why it doesn't work. I'm using the latest snapshot version. So here it goes. A simple rule with conjunction and disjunction but over a set of events.        when                $ldes : Set(size == 2) from collect(LoopDetectorEvent() over window:length(2))                (or LoopDetectorEvent($t1 : transportation == "LKW", $id1 : eventID) from $ldes                LoopDetectorEvent($t2 : transportation == "PKW", $id2 : eventID) from $ldes)                LoopDetectorEvent($t3 : transportation == "BUS", $id3 : eventID) from $ldes So, what the rule says: fire when there's a BUS event plus either a LKW or PKW event in the set. But, instead I get a big exception. It's posted at the end. Interestingly, it works if I don't use the Set, like this...        when                (or $e1 : LoopDetectorEvent($t1 : transportation == "PKW", $id1 : eventID) over window:length(1)                $e2 : LoopDetectorEvent($t2 : transportation == "LKW", $id2 : eventID) over window:length(1))                LoopDetectorEvent($t3 : transportation == "BUS", $id3 : eventID) over window:length(1) but that rule does not have the same meaning. So it's useless for me. Besides, it DOES work with the set if I just cut the third event out (the BUS event). What is wrong here? Thanks in advance. Kind regards! Oliver Exception in thread "Thread-2" java.lang.ClassCastException: org.drools.reteoo.InitialFactImpl cannot be cast to trafficsys.domain.events.LoopDetectorEvent        at org.drools.base.trafficsys.domain.events.LoopDetectorEvent446196$getTransportation.getValue(Unknown Source)        at org.drools.base.ClassFieldReader.getValue(ClassFieldReader.java:91)        at org.drools.base.evaluators.EqualityEvaluatorsDefinition$StringEqualEvaluator.evaluate(EqualityEvaluatorsDefinition.java:1961)        at org.drools.rule.LiteralRestriction.isAllowed(LiteralRestriction.java:92)        at org.drools.rule.LiteralConstraint.isAllowed(LiteralConstraint.java:109)        at org.drools.reteoo.FromNode.checkConstraintsAndPropagate(FromNode.java:264)        at org.drools.reteoo.FromNode.assertLeftTuple(FromNode.java:138)        at org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:189)        at org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:64)        at org.drools.reteoo.FromNode.checkConstraintsAndPropagate(FromNode.java:279)        at org.drools.reteoo.FromNode.assertLeftTuple(FromNode.java:138)        at org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:189)        at org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:64)        at org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:662)        at org.drools.reteoo.AccumulateNode.assertObject(AccumulateNode.java:270)        at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:450)        at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:378)        at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:190)        at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:145)        at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1187)        at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1089)        at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:893)        at org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:238)        at trafficsys.SessionInterface.insertAndFire(SessionInterface.java:133) -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Why-won-t-this-work-C... Sent from the Drools - User mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users