title: Orbeon 3.9 ANY User Interaction with form triggers a java.lang.NullPointerException Error
body: <p>We have a PHP app that uses Orbeon in the background to display forms to the users,
  Recently we had to come up with the solution for people with the 8080 port blocked so we have installed the jk_mod to serve Tomcat webapps in the vhost file as:</p>
  
  <pre><code>JkMount /orbeon/* geronimo_ajp13
  JkMount /ops/* geronimo_ajp13
  </code></pre>
  
  <p>Users are able to open Orbeon documents but as soon as they perform any Orbeon action (click in the table, submit form etc.) they get following Orbeon error:</p>
  
  <p><img src="https://i.stack.imgur.com/L8ieD.png" alt="enter image description here"></p>
  
  <p>Here is my Firebug response (200 ok) when Orbeon action gets triggered:</p>
  
  <p><img src="https://i.stack.imgur.com/qJrHQ.png" alt="enter image description here"></p>
  
  <p>And here is the orbeon.log error triggered:</p>
  
  <pre><code>    2012-06-21 12:19:21,796 INFO  ProcessorService  - /xforms-server - Received request
  2012-06-21 12:19:21,866 ERROR ProcessorService  - Exception at line 55, column 65 of oxf:/ops/xforms/xforms-server.xpl (reading processor output: name='response', id='x
  forms-response')
  java.lang.NullPointerException
          at org.orbeon.oxf.xforms.state.XFormsStateManager.checkUUIDInSession(XFormsStateManager.java:92)
          at org.orbeon.oxf.xforms.state.XFormsStateManager.findOrRestoreDocument(XFormsStateManager.java:277)
          at org.orbeon.oxf.xforms.processor.XFormsServer.doIt(XFormsServer.java:152)
          at org.orbeon.oxf.xforms.processor.XFormsServer.access$000(XFormsServer.java:56)
          at org.orbeon.oxf.xforms.processor.XFormsServer$1.readImpl(XFormsServer.java:88)
          at org.orbeon.oxf.processor.impl.ProcessorOutputImpl$TopLevelOutputFilter.read(ProcessorOutputImpl.java:263)
          at org.orbeon.oxf.processor.impl.ProcessorOutputImpl.read(ProcessorOutputImpl.java:406)
          at org.orbeon.oxf.processor.ProcessorImpl.readInputAsSAX(ProcessorImpl.java:260)
          at org.orbeon.oxf.processor.pipeline.TeeProcessor$TeeProcessorOutputImpl.readImpl(TeeProcessor.java:89)
          at org.orbeon.oxf.processor.impl.ProcessorOutputImpl$TopLevelOutputFilter.read(ProcessorOutputImpl.java:263)
          at org.orbeon.oxf.processor.impl.ProcessorOutputImpl.read(ProcessorOutputImpl.java:406)
          at org.orbeon.oxf.processor.ProcessorImpl.readInputAsSAX(ProcessorImpl.java:260)
          at org.orbeon.oxf.processor.ProcessorImpl.readInputAsTinyTree(ProcessorImpl.java:286)
          at org.orbeon.oxf.processor.ProcessorImpl$3.read(ProcessorImpl.java:315)
          at org.orbeon.oxf.processor.ProcessorImpl.readCacheInputAsObject(ProcessorImpl.java:365)
          at org.orbeon.oxf.processor.ProcessorImpl.readCacheInputAsObject(ProcessorImpl.java:330)
          at org.orbeon.oxf.processor.ProcessorImpl.readCacheInputAsTinyTree(ProcessorImpl.java:313)
          at org.orbeon.oxf.processor.pipeline.choose.ConcreteChooseProcessor.start(ConcreteChooseProcessor.java:186)
          at org.orbeon.oxf.processor.pipeline.PipelineProcessor$5.run(PipelineProcessor.java:661)
          at org.orbeon.oxf.processor.pipeline.PipelineProcessor.executeChildren(PipelineProcessor.java:726)
          at org.orbeon.oxf.processor.pipeline.PipelineProcessor.start(PipelineProcessor.java:658)
          at org.orbeon.oxf.processor.pipeline.choose.ConcreteChooseProcessor.start(ConcreteChooseProcessor.java:248)
          at org.orbeon.oxf.processor.pipeline.PipelineProcessor$5.run(PipelineProcessor.java:661)
          at org.orbeon.oxf.processor.pipeline.PipelineProcessor.executeChildren(PipelineProcessor.java:726)
          at org.orbeon.oxf.processor.pipeline.PipelineProcessor.start(PipelineProcessor.java:658)
          at org.orbeon.oxf.pipeline.InitUtils.runProcessor(InitUtils.java:89)
          at org.orbeon.oxf.webapp.ProcessorService.service(ProcessorService.java:97)
          at org.orbeon.oxf.servlet.OrbeonServletDelegate.service(OrbeonServletDelegate.java:133)
          at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
          at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
          at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
          at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
          at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
          at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
          at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
          at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
          at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
          at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:769)
          at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:698)
          at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:891)
          at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
          at java.lang.Thread.run(Thread.java:636)
  </code></pre>
  
  <p>Does anybody know what is going on?</p>