Java.lang.NullPointerException in ExternalContextImpl.dispatch()

Question

I have a JSP page that uses JSF/ADF-Faces that throws the following error 15 times whenever the page is refreshed. If I redirect to another page and redirect back the error does not occur. I have a dialogReturnListener() that updates the page with a ExternalContect().redirect() and this does not cause the NullPointerExceptions. But if I hit the refresh button or when I first enter the page I consistently get 15 NullPointerExcpetions.
This error has occurred consistently in EA16 and EA17 and I think in EA14. In both EA16 and EA17 the NullPointerException occured at the same point in com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:322)
I have tried removing lines of code from various parts of the JSP page but I always get 15 occurrances of this error whenever I update the page. I can't find anything in my page that happens 15 times.
The page works fine but the log file grows rather rapidly as the page gets refreshed often. The page contains a reference to an applet (using the <object> component) that requires a refresh from time to time.
05/07/09 21:55:42.140 CMSDKExplorer: Servlet error
java.lang.NullPointerException
     at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:322)
     at com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:130)
     at oracle.adfinternal.view.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:146)
     at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:87)
     at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
     at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:117)
     at javax.faces.webapp.FacesServlet.service(FacesServlet.java:198)
     at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) - Developer Preview 3].server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:61)
     at oracle.security.jazn.oc4j.JAZNFilter.doFilter(Unknown Source)
     at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) - Developer Preview 3].server.http.EvermindFilterChain.doFilter(EvermindFilterChain.java:15)
     at oracle.adfinternal.view.faces.webapp.AdfFacesFilterImpl._doFilterImpl(AdfFacesFilterImpl.java:310)
     at oracle.adfinternal.view.faces.webapp.AdfFacesFilterImpl.doFilter(AdfFacesFilterImpl.java:183)
     at oracle.adf.view.faces.webapp.AdfFacesFilter.doFilter(AdfFacesFilter.java:87)
     at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) - Developer Preview 3].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:670)
     at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) - Developer Preview 3].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:378)
     at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) - Developer Preview 3].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:869)
     at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) - Developer Preview 3].server.http.HttpRequestHandler.run(HttpRequestHandler.java:288)
     at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) - Developer Preview 3].server.http.HttpRequestHandler.run(HttpRequestHandler.java:120)
     at com.evermind[Oracle Containers for J2EE 10g (10.1.3.0.0) - Developer Preview 3].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:299)
     at java.lang.Thread.run(Thread.java:534)

Answer 1

The page in redirected to by the faces-config.xml file the same as all the other pages. I start off with an index.html which forwards to my LoginPage.jsp and that redirects to a HomePage which is one of 5 pages that share a parallel status on a <af:menuTabs> as follows:
<af:panelPage>
<f:facet name="menu1">
<af:menuTabs>
<af:commandMenuItem text="#{nls.Home}" selected="true" />
<af:commandMenuItem text="#{nls.Documents}" action="content" disabled="#{!LoginBean.docPageEnabled}" />
<af:commandMenuItem text="#{nls.Mapping}" action="map" disabled="#{!LoginBean.mapPageEnabled}" />
<af:commandMenuItem text="#{nls.Preferences}" action="prefs" />
<af:commandMenuItem text="#{nls.Administration}" action="admin" rendered="#{LoginBean.user.globalAdmin || LoginBean.user.groupAdmin }" />
</af:menuTabs>
</f:facet>
The HomePage (and all the other pages are configured in faces-config.xml as follows:
<from-view-id>/HomePage.jsp</from-view-id>
<navigation-case>
<description>Redirect to the map page</description>
<from-outcome>map</from-outcome>
<to-view-id>/MapPage.jsp</to-view-id>
<redirect/>
</navigation-case>
My web.xml and adf-faces-config.xml are set up as specified in the ADF release notes and Development Guidelines.