[rules-users] java.lang.NullPointerException at org.drools.reteoo.ReteooFactHandleFactory.newFactHandle(ReteooFactHandleFactory.java:56)

*Hi everyone! * *I'm loading from Guvnor5.3.0 the pkg below ** into my application. * *package* org.dfms.model; *import* org.dfms.model.observation.ACObservation; *import* org.dfms.model.situation.AccessControlEvent; *import* org.dfms.model.situation.SituationManager; *import* org.dfms.model.situation.Event; *import* org.dfms.model.mapfeature.AccessControlPoint; *import* java.util.HashSet; *import* java.util.ArrayList; *declare* ACObservation @role(event) *end* *declare* AccessControlEvent @role(event) *end* *rule* "AccessControl" *no-loop* *when* $obs : ACObservation( $sensorid : sensorId, $location : location ) over window:length(1) *from* entry-point access_control *then* *insert*( SituationManager.createAccessControlEvent( $obs, "Access Control Detection", Event.THREAT_NO, $location, $sensorid )); *end* *When the rule is executed the application get this exception:* [*java*] ERROR [2012-07-20 14:32:17,422] [Thread-19] (* ExpertSystemManager.java:162*) - *java.lang.NullPointerException* [*java*] *java.lang.NullPointerException* [*java*] at org.drools.reteoo.ReteooFactHandleFactory.newFactHandle(* ReteooFactHandleFactory.java:56*) [*java*] at org.drools.common.AbstractFactHandleFactory.newFactHandle(* AbstractFactHandleFactory.java:80*) [*java*] at org.drools.common.AbstractFactHandleFactory.newFactHandle(* AbstractFactHandleFactory.java:65*) [*java*] at org.drools.common.NamedEntryPoint.createHandle(* NamedEntryPoint.java:720*) [*java*] at org.drools.common.NamedEntryPoint.insert(* NamedEntryPoint.java:280*) [*java*] at org.drools.common.NamedEntryPoint.insert(* NamedEntryPoint.java:116*) [*java*] at org.drools.common.NamedEntryPoint.insert(* NamedEntryPoint.java:48*) [*java*] at org.tass.utils.ExpertSystemManager.insertObservation( *ExpertSystemManager.java:156*) [*java*] at org.tass.vsensor.ExpertVS.dataAvailable(* ExpertVS.java:59*) [*java*] at gsn.beans.InputStream.executeQuery(* InputStream.java:277*) [*java*] at gsn.beans.StreamSource.windowSlided(* StreamSource.java:325*) [*java*] at gsn.beans.windowing.SQLViewQueryRewriter.dataAvailable(* SQLViewQueryRewriter.java:83*) [*java*] at gsn.beans.windowing.TupleBasedSlidingHandler.dataAvailable(* TupleBasedSlidingHandler.java:56*) [*java*] at gsn.wrappers.AbstractWrapper.postStreamElement(* AbstractWrapper.java:222*) [*java*] at gsn.http.rest.LocalDeliveryWrapper.writeStreamElement(* LocalDeliveryWrapper.java:147*) [*java*] at gsn.http.rest.DefaultDistributionRequest.deliverStreamElement(* DefaultDistributionRequest.java:57*) [*java*] at gsn.DataDistributer.flushStreamElement(* DataDistributer.java:165*) [*java*] at gsn.DataDistributer.run(*DataDistributer.java:220*) [*java*] at java.lang.Thread.run(*Thread.java:662*) *How can I solve this issue?* * Thank you in advance, Carolina Pellecchia*