[rules-users] odd error when trying to update a fact in working memory

[Eric Miles]

Can anyone tell me what this means?  It seems as though the fact is
being updated elsewhere and is causing the fact handle to not be found,
but I have no idea how to go about figuring that out.  Is this even what
this error message is trying to tell me?

java.lang.NullPointerException
	org.drools.util.AbstractHashTable$EqualityEquals.hashCodeOf(AbstractHashTable.java:325)
	org.drools.util.ObjectHashMap.remove(ObjectHashMap.java:96)
	org.drools.reteoo.FromNode.retractTuple(FromNode.java:110)
	org.drools.reteoo.CompositeTupleSinkAdapter.createAndPropagateRetractTuple(CompositeTupleSinkAdapter.java:83)
	org.drools.reteoo.LeftInputAdapterNode.retractObject(LeftInputAdapterNode.java:151)
	org.drools.reteoo.CompositeObjectSinkAdapter.propagateRetractObject(CompositeObjectSinkAdapter.java:375)
	org.drools.reteoo.ObjectTypeNode.retractObject(ObjectTypeNode.java:180)
	org.drools.reteoo.Rete.retractObject(Rete.java:214)
	org.drools.reteoo.ReteooRuleBase.retractObject(ReteooRuleBase.java:211)
	org.drools.reteoo.ReteooWorkingMemory.doRetract(ReteooWorkingMemory.java:79)
	org.drools.common.AbstractWorkingMemory.update(AbstractWorkingMemory.java:1231)
	org.drools.base.DefaultKnowledgeHelper.update(DefaultKnowledgeHelper.java:96)
	com.kronos.webta.service.smarttime.rules.Rule_Schedule_Day_0.consequence(Rule_Schedule_Day_0.java:20)
	com.kronos.webta.service.smarttime.rules.Rule_Schedule_Day_0ConsequenceInvoker.evaluate(Rule_Schedule_Day_0ConsequenceInvoker.java:22)