InvalidViewPortIdException: View port ID '1d2gjji9s1_27 is invalid.

Question

The scenario is that I am navigating from one view (by clicking on a command link in a table) to another view with in a bounded taskflow . in the second view, I click on a command link to navigate back to the first task flow. Till here it works fine. When I select another command link in the table, I am get InvalidViewPortIdException in the page. I close the alert message popup and click on any command link in the table it works fine. I do not get this exception at all after this.
To reproduce this issue again, I logout and login again to the adf application and do the steps mentioned above. The exception stacktrace is as follows.
<Nov 26, 2012 6:25:04 AM PST> <Error> <oracle.adfinternal.view.faces.config.rich.RegistrationConfigurator> <BEA-000000> <ADF_FACES-60096:Server Exception during PPR, #1
oracle.adf.controller.internal.InvalidViewPortIdException: ADFC-14000: View port ID '1d2gjji9s1_27' is invalid.
     at oracle.adfinternal.controller.state.ControllerState.setCurrentViewPort(ControllerState.java:1402)
     at oracle.adfinternal.controller.state.ViewPortContextImpl.deliverNavigationEvents(ViewPortContextImpl.java:972)
     at oracle.adfinternal.controller.application.SyncNavigationStateListener.afterPhase(SyncNavigationStateListener.java:114)
     at oracle.adfinternal.controller.lifecycle.ADFLifecycleImpl$PagePhaseListenerWrapper.afterPhase(ADFLifecycleImpl.java:539)
     at oracle.adfinternal.controller.lifecycle.LifecycleImpl.internalDispatchAfterEvent(LifecycleImpl.java:120)
     at oracle.adfinternal.controller.lifecycle.LifecycleImpl.dispatchAfterPagePhaseEvent(LifecycleImpl.java:171)
     at oracle.adfinternal.controller.faces.lifecycle.ADFPhaseListener$PhaseInvokerImpl.dispatchAfterPagePhaseEvent(ADFPhaseListener.java:313)
     at oracle.adfinternal.controller.faces.lifecycle.ADFPhaseListener.afterPhase(ADFPhaseListener.java:87)
     at oracle.adfinternal.controller.faces.lifecycle.ADFLifecyclePhaseListener.afterPhase(ADFLifecyclePhaseListener.java:54)
     at oracle.adfinternal.view.faces.lifecycle.LifecycleImpl._executePhase(LifecycleImpl.java:520)
     at oracle.adfinternal.view.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:207)
     at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265)
     at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
     at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:301)
     at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:27)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.help.web.rich.OHWFilter.doFilter(Unknown Source)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.adf.model.servlet.ADFBindingFilter.doFilter(ADFBindingFilter.java:205)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.adfinternal.view.faces.webapp.rich.RegistrationFilter.doFilter(RegistrationFilter.java:128)
     at org.apache.myfaces.trinidadinternal.webapp.TrinidadFilterImpl$FilterListChain.doFilter(TrinidadFilterImpl.java:447)
     at oracle.adfinternal.view.faces.activedata.AdsFilter.doFilter(AdsFilter.java:60)
     at org.apache.myfaces.trinidadinternal.webapp.TrinidadFilterImpl$FilterListChain.doFilter(TrinidadFilterImpl.java:447)
     at org.apache.myfaces.trinidadinternal.webapp.TrinidadFilterImpl._doFilterImpl(TrinidadFilterImpl.java:271)
     at org.apache.myfaces.trinidadinternal.webapp.TrinidadFilterImpl.doFilter(TrinidadFilterImpl.java:177)
     at org.apache.myfaces.trinidad.webapp.TrinidadFilter.doFilter(TrinidadFilter.java:92)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.adf.library.webapp.LibraryFilter.doFilter(LibraryFilter.java:181)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.security.jps.ee.http.JpsAbsFilter$1.run(JpsAbsFilter.java:119)
     at oracle.security.jps.util.JpsSubject.doAsPrivileged(JpsSubject.java:315)
     at oracle.security.jps.ee.util.JpsPlatformUtil.runJaasMode(JpsPlatformUtil.java:460)
     at oracle.security.jps.ee.http.JpsAbsFilter.runJaasMode(JpsAbsFilter.java:103)
     at oracle.security.jps.ee.http.JpsAbsFilter.doFilter(JpsAbsFilter.java:171)
     at oracle.security.jps.ee.http.JpsFilter.doFilter(JpsFilter.java:71)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.security.jps.ee.http.JpsAbsFilter$1.run(JpsAbsFilter.java:119)
     at oracle.security.jps.util.JpsSubject.doAsPrivileged(JpsSubject.java:315)
     at oracle.security.jps.ee.util.JpsPlatformUtil.runJaasMode(JpsPlatformUtil.java:460)
     at oracle.security.jps.ee.http.JpsAbsFilter.runJaasMode(JpsAbsFilter.java:103)
     at oracle.security.jps.ee.http.JpsAbsFilter.doFilter(JpsAbsFilter.java:171)
     at oracle.security.jps.ee.http.JpsFilter.doFilter(JpsFilter.java:71)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.security.wls.filter.SSOSessionSynchronizationFilter.doFilter(SSOSessionSynchronizationFilter.java:419)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.dms.servlet.DMSServletFilter.doFilter(DMSServletFilter.java:163)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at oracle.security.jps.ee.http.JpsAbsFilter$1.run(JpsAbsFilter.java:119)
     at oracle.security.jps.util.JpsSubject.doAsPrivileged(JpsSubject.java:315)
     at oracle.security.jps.ee.util.JpsPlatformUtil.runJaasMode(JpsPlatformUtil.java:460)
     at oracle.security.jps.ee.http.JpsAbsFilter.runJaasMode(JpsAbsFilter.java:103)
     at oracle.security.jps.ee.http.JpsAbsFilter.doFilter(JpsAbsFilter.java:171)
     at oracle.security.jps.ee.http.JpsFilter.doFilter(JpsFilter.java:71)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:27)
     at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:57)
     at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3730)
     at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3696)
     at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
     at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
     at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2273)
     at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
     at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1490)
     at weblogic.work.ExecuteThread.execute(ExecuteThread.java:256)
     at weblogic.work.ExecuteThread.run(ExecuteThread.java:221)
>

Answer 1

Hi Frank,
You guessed it right. The design for the outer taskflow is as follows
View1 and view2 represents two view activities. View1 contains the table and on click of a link navigates to view2 based on control flow rule. View2 contains a commandlink (to go back to view1) and a region.
<control-flow-rule id="__1833">
<from-activity-id id="__1943">view1</from-activity-id>
<control-flow-case>
<from-outcome>SUCCESS</from-outcome>
<to-activity-id>view2</to-activity-id>
</control-flow-case>
</control-flow-rule>
<control-flow-rule>
<from-activity-id>view2</from-activity-id>
<control-flow-case>
<from-outcome>GO_BACK</from-outcome>
<to-activity-id>view1</to-activity-id>
</control-flow-case>
</control-flow-rule>
view1.jsff
=============
<af:column headerText="#{wlist_msg.LABEL_DETAILS_PROCESS_NAME}" sortable="#{pageFlowScope.taskView.taskList.sortable}" sortProperty="processName"
id="taskTableProcessNameColumn" >
<*af:commandLink* id="processName" text="#{tabledata.processName}"
action="*SUCCESS*">
<af:setActionListener from="#{tabledata.processId}"
to="#{pageFlowScope.instanceId}"/>
</af:commandLink>
</af:column>
view2.jsff
==============
<?xml version='1.0' encoding='US-ASCII'?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:af="http://xmlns.oracle.com/adf/faces/rich"
version="2.1">
<jsp:directive.page contentType="text/html;charset=utf-8"/>
<af:panelStretchLayout id="processInstanceDetailsFrame" >
<f:facet name="top">
<af:panelGroupLayout layout="vertical">
<*af:commandLink* text="#{wlist_msg.SHOW_TASK_LIST}" id="clstl"
action="*GO_BACK*"/>
<af:outputText value="#{pageFlowScope.instanceId}"/>
</af:panelGroupLayout>
</f:facet>
<f:facet name="center">
<*af:region* value="#{bindings.processInstanceDetailTaskflow1.regionModel}" id="r1"/>
</f:facet>
</af:panelStretchLayout>
</jsp:root>