Hi, I am working with Drools 5.2.0 final and Guvnor also the same version. application server: GateIn-3.1.0-FINAL-jbossas I have uploaded a java model and defined a rule using that model. I did validation of the package and build also. After that in my web application, when I am trying to access the knowledgebase I am getting error in server console as mentioned below. 21:22:28,450 INFO [STDOUT] 1 21:22:28,629 INFO [STDOUT] 2 21:22:28,638 INFO [STDOUT] 3 21:22:28,834 INFO [STDOUT] 4 21:22:28,840 INFO [STDOUT] 5 21:22:28,844 INFO [STDOUT] 6 21:22:28,886 INFO [STDOUT] 7 21:22:28,890 INFO [STDOUT] 8 21:22:28,891 INFO [STDOUT] kbase:org.drools.impl.KnowledgeBaseImpl@66c790c9 kag ent: org.drools.agent.impl.KnowledgeAgentImpl@37f2b0d6 21:22:29,158 INFO [STDOUT] INFO 26-07 21:22:29,157 (NilAuthenticator.java:auth enticate:35) All users are guests. 21:22:29,163 INFO [STDOUT] INFO 26-07 21:22:29,163 (RepositoryServlet.java:all owUser:114) null authenticated for rest api 21:22:29,164 INFO [STDOUT] INFO 26-07 21:22:29,164 (PackageDeploymentServlet.j ava:execute:141) PackageName: sam 21:22:29,164 INFO [STDOUT] INFO 26-07 21:22:29,164 (PackageDeploymentServlet.j ava:execute:142) PackageVersion: LATEST 21:22:29,165 INFO [STDOUT] INFO 26-07 21:22:29,165 (PackageDeploymentServlet.j ava:execute:143) PackageIsLatest: true 21:22:29,165 INFO [STDOUT] INFO 26-07 21:22:29,165 (PackageDeploymentServlet.j ava:execute:144) PackageIsSource: false 21:22:29,172 INFO [STDOUT] error... 21:22:29,173 ERROR [STDERR] java.lang.NullPointerException 21:22:29,174 ERROR [STDERR] at org.drools.agent.impl.KnowledgeAgentImpl.proc essChangeSet(KnowledgeAgentImpl.java:223) 21:22:29,175 ERROR [STDERR] at org.drools.agent.impl.KnowledgeAgentImpl.appl yChangeSet(KnowledgeAgentImpl.java:189) 21:22:29,175 ERROR [STDERR] at org.drools.agent.impl.KnowledgeAgentImpl.appl yChangeSet(KnowledgeAgentImpl.java:174) 21:22:29,175 ERROR [STDERR] at org.apache.jsp.index1_jsp._jspService(index1_ jsp.java:124) 21:22:29,175 ERROR [STDERR] at org.apache.jasper.runtime.HttpJspBase.service (HttpJspBase.java:70) 21:22:29,175 ERROR [STDERR] at javax.servlet.http.HttpServlet.service(HttpSe rvlet.java:717) 21:22:29,176 ERROR [STDERR] at org.apache.jasper.servlet.JspServletWrapper.s ervice(JspServletWrapper.java:369) 21:22:29,176 ERROR [STDERR] at org.apache.jasper.servlet.JspServlet.serviceJ spFile(JspServlet.java:322) 21:22:29,176 ERROR [STDERR] at org.apache.jasper.servlet.JspServlet.service( JspServlet.java:249) 21:22:29,176 ERROR [STDERR] at javax.servlet.http.HttpServlet.service(HttpSe rvlet.java:717) 21:22:29,176 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterCha in.internalDoFilter(ApplicationFilterChain.java:290) 21:22:29,176 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterCha in.doFilter(ApplicationFilterChain.java:206) 21:22:29,177 ERROR [STDERR] at org.jboss.web.tomcat.filters.ReplyHeaderFilte r.doFilter(ReplyHeaderFilter.java:96) 21:22:29,180 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterCha in.internalDoFilter(ApplicationFilterChain.java:235) 21:22:29,180 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterCha in.doFilter(ApplicationFilterChain.java:206) 21:22:29,180 ERROR [STDERR] at org.apache.catalina.core.StandardWrapperValve .invoke(StandardWrapperValve.java:235) 21:22:29,180 ERROR [STDERR] at org.apache.catalina.core.StandardContextValve .invoke(StandardContextValve.java:191) 21:22:29,180 ERROR [STDERR] at org.jboss.web.tomcat.security.SecurityAssocia tionValve.invoke(SecurityAssociationValve.java:190) 21:22:29,181 ERROR [STDERR] at org.jboss.web.tomcat.security.JaccContextValv e.invoke(JaccContextValve.java:92) 21:22:29,181 ERROR [STDERR] at org.jboss.web.tomcat.security.SecurityContext EstablishmentValve.process(SecurityContextEstablishmentValve.java:126) 21:22:29,181 ERROR [STDERR] at org.jboss.web.tomcat.security.SecurityContext EstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70) 21:22:29,181 ERROR [STDERR] at org.apache.catalina.core.StandardHostValve.in voke(StandardHostValve.java:127) 21:22:29,181 ERROR [STDERR] at org.apache.catalina.valves.ErrorReportValve.i nvoke(ErrorReportValve.java:102) 21:22:29,182 ERROR [STDERR] at org.jboss.web.tomcat.service.jca.CachedConnec tionValve.invoke(CachedConnectionValve.java:158) 21:22:29,182 ERROR [STDERR] at org.apache.catalina.core.StandardEngineValve. invoke(StandardEngineValve.java:109) 21:22:29,182 ERROR [STDERR] at org.apache.catalina.connector.CoyoteAdapter.s ervice(CoyoteAdapter.java:330) 21:22:29,182 ERROR [STDERR] at org.apache.coyote.http11.Http11Processor.proc ess(Http11Processor.java:829) 21:22:29,182 ERROR [STDERR] at org.apache.coyote.http11.Http11Protocol$Http1 1ConnectionHandler.process(Http11Protocol.java:598) 21:22:29,183 ERROR [STDERR] at org.apache.tomcat.util.net.JIoEndpoint$Worker .run(JIoEndpoint.java:447) 21:22:29,183 ERROR [STDERR] at java.lang.Thread.run(Thread.java:662) ------------- the code snippet for above exception System.out.println("1"); // knowledge base configuration KnowledgeBaseConfiguration kbaseConf = KnowledgeBaseFactory .newKnowledgeBaseConfiguration(); System.out.println("2"); kbaseConf.setOption(EventProcessingOption.STREAM); System.out.println("3"); // knowledge base KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(kbaseConf); System.out.println("4"); KnowledgeAgentConfiguration kagentConf = KnowledgeAgentFactory .newKnowledgeAgentConfiguration(); System.out.println("5"); // enable incremental knowledge base build kagentConf.setProperty("drools.agent.newInstance", "false"); System.out.println("6"); KnowledgeAgent kagent = KnowledgeAgentFactory.newKnowledgeAgent( "demoAgent", kbase, kagentConf); System.out.println("7"); Resource changeset = null; changeset = ResourceFactory.newUrlResource("http://127.0.0.1:8080/guvnor/org.drools.guvnor.Guvnor/package/demo/LATEST/ChangeSet.xml"); System.out.println("8"); System.out.println("kbase:"+kbase+" kagent: "+kagent); *kagent.applyChangeSet(changeset);* System.out.println("9"); System.out.println("kbase:"+kbase+" kagent: "+kagent); kagent.dispose(); System.out.println("readKnowledgeBase() at end............"); ------ changeset file content <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 http://anonsvn.jboss.org/repos/labs/labs/jbossrules/trunk/drools-api/src/... <add <resource source='http://127.0.0.1:8080/guvnor/org.drools.guvnor.Guvnor/package/demo/LATEST' type='PKG' basicAuthentication='enabled' username='admin' password='admin' / </add</change-set ---------- I am able to get the knowledgebase using java application, but I am not able to get the knowledgebase from web application. please suggest me, what could be the reason for this and how to resolve this. -- View this message in context: http://drools.46999.n3.nabble.com/Not-able-to-get-the-knowledgeBase-from-... Sent from the Drools: User forum mailing list archive at Nabble.com.