VC-Error: isSingleton() of a null object loaded from local variable 'parent'

[sergej_heinrich]

Hi folks,

some user get this error. Not every time, not on the same place (on any click in the vc-application). Can someone give me an idea how to solve this or where to look like?

Stacktrace:

500 Internal Server Error is returned for HTTP request [https://portal.stadt.essen.de:50000/webdynpro/resources/sap.com/pb/PageBuilder]: 
  component [dispatcher], 
  web module [webdynpro/resources/sap.com/de.essen.rechnungseingangsbuch_impl], 
  application [sap.com/de.essen.rechnungseingangsbuch_impl], 
  DC name [sap.com/de.essen.rechnungseingangsbuch_impl], 
  CSN component[], 
  problem categorization [], 
  internal categorization [-773710491]. 

[EXCEPTION]
java.lang.NullPointerException: while trying to invoke the method com.sap.tc.webdynpro.progmodel.context.NodeInfo.isSingleton() of a null object loaded from local variable 'parent'
at com.sap.tc.webdynpro.progmodel.context.MappedNodeInfo.isSingleton(MappedNodeInfo.java:66)
at com.sap.tc.webdynpro.progmodel.context.Node.getChildNodeInternal(Node.java:980)
at com.sap.tc.webdynpro.progmodel.context.Paths.followPath(Paths.java:1422)
at com.sap.tc.webdynpro.progmodel.context.Paths.followPath(Paths.java:1393)
at com.sap.tc.webdynpro.progmodel.context.Paths.createAttributePointer(Paths.java:175)
at com.sap.tc.webdynpro.progmodel.context.Paths.createAttributePointerExt(Paths.java:190)
at com.sap.tc.webdynpro.clientserver.uielib.standard.impl.AbstractDropDownByKey.getSelectedKey(AbstractDropDownByKey.java:508)
at com.sap.tc.wd4vc.core.std.interactors.pane.Generic.wdDoModifyView(Generic.java:339)
at com.sap.tc.wd4vc.core.std.interactors.pane.wdp.InternalGeneric.wdDoModifyView(InternalGeneric.java:260)
at com.sap.tc.webdynpro.progmodel.generation.DelegatingView.doModifyView(DelegatingView.java:94)
at com.sap.tc.webdynpro.progmodel.view.View.modifyView(View.java:746)
at com.sap.tc.webdynpro.progmodel.window.ViewController.modifyView(ViewController.java:254)
at com.sap.tc.webdynpro.clientserver.cal.ClientComponent.doModifyView(ClientComponent.java:432)
at com.sap.tc.webdynpro.clientserver.cal.ClientComponent.doModifyView(ClientComponent.java:438)
at com.sap.tc.webdynpro.clientserver.cal.ClientComponent.doModifyView(ClientComponent.java:438)
at com.sap.tc.webdynpro.clientserver.phases.ModifyViewPhase.execute(ModifyViewPhase.java:69)
at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.processRequestPartly(WindowPhaseModel.java:162)
at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.doProcessRequest(WindowPhaseModel.java:110)
at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.processRequest(WindowPhaseModel.java:97)
at com.sap.tc.webdynpro.clientserver.window.WebDynproWindow.processRequest(WebDynproWindow.java:515)
at com.sap.tc.webdynpro.clientserver.cal.AbstractClient.executeTasks(AbstractClient.java:58)
at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.doExecute(ClientApplication.java:1671)
at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.doProcessing(ClientApplication.java:1485)
at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doApplicationProcessingEmbedded(ApplicationSession.java:919)
at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doApplicationProcessing(ApplicationSession.java:878)
at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doProcessing(ApplicationSession.java:357)
at com.sap.tc.webdynpro.clientserver.session.RequestManager.doProcessing(RequestManager.java:326)
at com.sap.tc.webdynpro.serverimpl.core.sessionctx.AbstractExecutionContextDispatcher.delegateToRequestManager(AbstractExecutionContextDispatcher.java:62)
at com.sap.tc.webdynpro.serverimpl.wdc.sessionctx.DispatchHandlerForRequestManager.service(DispatchHandlerForRequestManager.java:39)
at com.sap.tc.webdynpro.serverimpl.wdc.sessionctx.DispatchHandlerForRequestManager.service(DispatchHandlerForRequestManager.java:46)
at com.sap.engine.services.servlets_jsp.server.deploy.impl.module.IRequestDispatcherImpl.dispatch(IRequestDispatcherImpl.java:270)
at com.sap.tc.webdynpro.serverimpl.wdc.sessionctx.ExecutionContextDispatcher.dispatchToAppContext(ExecutionContextDispatcher.java:68)
at com.sap.tc.webdynpro.serverimpl.core.sessionctx.AbstractExecutionContextDispatcher.dispatch(AbstractExecutionContextDispatcher.java:53)
at com.sap.tc.webdynpro.clientserver.session.RequestManager.doProcessing(RequestManager.java:245)
at com.sap.tc.webdynpro.clientserver.embedding.JavaApplicationProxy$Runner.callRequestManager(JavaApplicationProxy.java:1244)
at com.sap.tc.webdynpro.clientserver.embedding.JavaApplicationProxy$Runner.callEmbeddedApplication(JavaApplicationProxy.java:1122)
at com.sap.tc.webdynpro.clientserver.embedding.JavaApplicationProxy$SendDataAndProcessActionCommand.doExecute(JavaApplicationProxy.java:1605)
at com.sap.tc.webdynpro.clientserver.embedding.JavaApplicationProxy$AbstractCommand.execute(JavaApplicationProxy.java:1488)
at com.sap.tc.webdynpro.clientserver.embedding.JavaApplicationProxy$Runner.execute(JavaApplicationProxy.java:1028)
at com.sap.tc.webdynpro.clientserver.embedding.JavaApplicationProxy.execute(JavaApplicationProxy.java:859)
at com.sap.tc.webdynpro.clientserver.embedding.JavaApplicationProxy.sendDataAndProcessAction(JavaApplicationProxy.java:468)
at com.sap.tc.webdynpro.portal.pb.impl.JavaApplicationProxyAdapter.sendDataAndProcessAction(JavaApplicationProxyAdapter.java:191)
at com.sap.portal.pb.PageBuilder.updateApplications(PageBuilder.java:1698)
at com.sap.portal.pb.PageBuilder.SendDataAndProcessAction(PageBuilder.java:369)
at com.sap.portal.pb.PageBuilder$PhaseListenerImpl.doPhase(PageBuilder.java:2123)
at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.processPhaseListener(WindowPhaseModel.java:251)
at com.sap.tc.webdynpro.clientserver.phases.PortalDispatchPhase.execute(PortalDispatchPhase.java:50)
at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.processRequestPartly(WindowPhaseModel.java:162)
at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.doProcessRequest(WindowPhaseModel.java:110)
at com.sap.tc.webdynpro.clientserver.window.WindowPhaseModel.processRequest(WindowPhaseModel.java:97)
at com.sap.tc.webdynpro.clientserver.window.WebDynproWindow.processRequest(WebDynproWindow.java:515)
at com.sap.tc.webdynpro.clientserver.cal.AbstractClient.executeTasks(AbstractClient.java:58)
at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.doExecute(ClientApplication.java:1671)
at com.sap.tc.webdynpro.clientserver.cal.ClientApplication.doProcessing(ClientApplication.java:1485)
at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doApplicationProcessingStandalone(ApplicationSession.java:908)
at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doApplicationProcessing(ApplicationSession.java:880)
at com.sap.tc.webdynpro.clientserver.session.ApplicationSession.doProcessing(ApplicationSession.java:357)
at com.sap.tc.webdynpro.clientserver.session.RequestManager.doProcessing(RequestManager.java:326)
at com.sap.tc.webdynpro.serverimpl.core.AbstractDispatcherServlet.doContent(AbstractDispatcherServlet.java:87)
at com.sap.tc.webdynpro.serverimpl.wdc.DispatcherServlet.doContent(DispatcherServlet.java:89)
at com.sap.tc.webdynpro.serverimpl.core.AbstractDispatcherServlet.doPost(AbstractDispatcherServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:754)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at com.sap.engine.services.servlets_jsp.server.Invokable.invoke(Invokable.java:152)
at com.sap.engine.services.servlets_jsp.server.Invokable.invoke(Invokable.java:38)
at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.runServlet(HttpHandlerImpl.java:457)
at com.sap.engine.services.servlets_jsp.server.HttpHandlerImpl.handleRequest(HttpHandlerImpl.java:210)
at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:441)
at com.sap.engine.services.httpserver.server.RequestAnalizer.startServlet(RequestAnalizer.java:430)
at com.sap.engine.services.servlets_jsp.filters.DSRWebContainerFilter.process(DSRWebContainerFilter.java:38)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.servlets_jsp.filters.ServletSelector.process(ServletSelector.java:81)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.servlets_jsp.filters.ApplicationSelector.process(ApplicationSelector.java:278)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.httpserver.filters.WebContainerInvoker.process(WebContainerInvoker.java:81)
at com.sap.engine.services.httpserver.chain.HostFilter.process(HostFilter.java:9)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.httpserver.filters.ResponseLogWriter.process(ResponseLogWriter.java:60)
at com.sap.engine.services.httpserver.chain.HostFilter.process(HostFilter.java:9)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.httpserver.filters.DefineHostFilter.process(DefineHostFilter.java:27)
at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.httpserver.filters.MonitoringFilter.process(MonitoringFilter.java:29)
at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.httpserver.filters.SessionSizeFilter.process(SessionSizeFilter.java:26)
at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.httpserver.filters.MemoryStatisticFilter.process(MemoryStatisticFilter.java:57)
at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.httpserver.filters.DSRHttpFilter.process(DSRHttpFilter.java:43)
at com.sap.engine.services.httpserver.chain.ServerFilter.process(ServerFilter.java:12)
at com.sap.engine.services.httpserver.chain.AbstractChain.process(AbstractChain.java:78)
at com.sap.engine.services.httpserver.server.Processor.chainedRequest(Processor.java:475)
at com.sap.engine.services.httpserver.server.Processor$FCAProcessorThread.process(Processor.java:269)
at com.sap.engine.services.httpserver.server.rcm.RequestProcessorThread.run(RequestProcessorThread.java:56)
at com.sap.engine.core.thread.execution.Executable.run(Executable.java:122)
at com.sap.engine.core.thread.execution.Executable.run(Executable.java:101)
at com.sap.engine.core.thread.execution.CentralExecutor$SingleThread.run(CentralExecutor.java:328)

[Former Member]

Hello Sergej,

In order to help you with this error I would need the VC
model that generates it. It is not clear from the error you attached if the
issue is caused by Web Dynpro or Visual Composer .

In order to proceed with the investigation, please open a
Customer Incident.

Best regards,

Betty

[sergej_heinrich]

Hi Betty,

thanks for your reply. What do you mean with VC model? An export from the whole application via VC? The application is based on own R/3-services. I think an import & test would be difficult.

I can not reproduce the error, but I see that the error ist comming up few times a day from different users. After the error the user must restart the application and fill the whole form again. Thats not fine.

Best regards,

Sergej

[Former Member]

Hi Sergej,

Yes, I mean the export of the Visual Composer application,
using the Model -> Export option. You should obtain a .zip file with the
same name with the Visual Composer model.

I know that I won’t be able to run it locally but I am interested
to see the elements in the model.

Best regards,

Betty

[sergej_heinrich]

Hi Betty,

I've reported a customer incident with the model as zip-File. #25603 / 2015

Best regards