[rules-users] KnowledgeAgent exception while trying to deserialize KnowledgeDefinitionsPackage

I'm getting the following error when I attempt to run my Drools application. I recently upgraded from Drools 5.0.1 and Guvnor 5.0.1 to 5.1.1 (for both). I've looked through the rules-users list and I found the issue with the XML Change Set (authentication), which I've addressed (XML listed at the bottom), but I'm still getting the error. Does anyone have any ideas or can point me in a particular direction? Thanks Error: [2010:12:337 09:12:373:debug] KnowledgeAgent mapping resource=[ClassPathResource path='ruleflow.rf'] to KnowledgeDefinition=org.drools.ruleflow.core.RuleFlowProcess@2d89ba2a [2010:12:337 09:12:373:exception] java.lang.RuntimeException: KnowledgeAgent exception while trying to deserialize KnowledgeDefinitionsPackage at org.drools.agent.impl.KnowledgeAgentImpl.addResourcesToKnowledgeBase(Kno wledgeAgentImpl.java:914) at org.drools.agent.impl.KnowledgeAgentImpl.rebuildResources(KnowledgeAgent Impl.java:704) at org.drools.agent.impl.KnowledgeAgentImpl.buildKnowledgeBase(KnowledgeAge ntImpl.java:584) at org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentIm pl.java:185) at org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentIm pl.java:168) at com.agencyawards2.RuleSessionProviderFactory.getSessionFactory(RuleSessi onProviderFactory.java:102) at com.agencyawards2.RuleSessionProviderFactory.getProvider(RuleSessionProv iderFactory.java:30) at com.agencyawards2.RunRules.runRules(RunRules.java:25) at com.agencyawards2.DroolsTest.main(DroolsTest.java:36) Caused by: java.lang.NullPointerException at org.drools.process.core.impl.ProcessImpl.equals(ProcessImpl.java:134) at java.util.HashMap.put(Unknown Source) at java.util.HashSet.add(Unknown Source) at org.drools.agent.impl.KnowledgeAgentImpl$RegisteredResourceMap.putDefini tion(KnowledgeAgentImpl.java:1150) at org.drools.agent.impl.KnowledgeAgentImpl.addDefinitionMapping(KnowledgeA gentImpl.java:1037) at org.drools.agent.impl.KnowledgeAgentImpl.buildResourceMapping(KnowledgeA gentImpl.java:496) at org.drools.agent.impl.KnowledgeAgentImpl.buildResourceMapping(KnowledgeA gentImpl.java:443) at org.drools.agent.impl.KnowledgeAgentImpl.addResourcesToKnowledgeBase(Kno wledgeAgentImpl.java:912) ... 8 more Change Set: <?xml version="1.0" encoding="UTF-8" ?> - <change-set xmlns="http://drools.org/drools-5.0/change-set" xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xs:schemaLocation="http://drools.org/drools-5.0/change-set drools-change-set-5.0.xsd"> - <add> <resource source="http://localhost:8080/drools-guvnor/org.drools.guvnor.Guvnor/pac kage/com.agencyawards2/LATEST" type="PKG" basicAuthentication="enabled" username="admin" password="admin" /> </add> </change-set>