Null pointer exception in EP 5

Hello,

i'm developing a java application with HTMLB in EP 5.0,

but when i try to see the developed pages sometimes appears an error and other times appears the page, and when i'm testing the page sometimes appears the error also, and other times all runs fine...

Somebody can tell me how can solve this problem ???

Thanks...

The error page is this:(Sorry for paste all error...)

An exception occurs during the component rendering

com.sapportals.portal.prt.component.PortalComponentException: Original exception: java.lang.NullPointerException

at pagelet._sapportalsjsp_menu.doContent_sapportalsjsp_menu.java:2911)

at com.sapportals.portal.prt.component.AbstractPortalComponent.service(AbstractPortalComponent.java:127)

at com.sapportals.portal.prt.core.broker.PortalComponentItemFacade.service(PortalComponentItemFacade.java:363)

at com.sapportals.portal.prt.core.broker.PortalComponentItem.service(PortalComponentItem.java:1705)

at com.sapportals.portal.prt.core.PortalRequestManager.dispatchRequest(PortalRequestManager.java:373)

at com.sapportals.portal.prt.component.PortalComponentResponse.include(PortalComponentResponse.java:246)

at com.sapportals.portal.htmlb.page.JSPDynPage.doOutput(JSPDynPage.java:76)

at com.sapportals.htmlb.page.PageProcessor.handleRequest(PageProcessor.java:102)

at com.sapportals.portal.htmlb.page.PageProcessorComponent.doContent(PageProcessorComponent.java:139)

at com.sapportals.portal.prt.component.AbstractPortalComponent.service(AbstractPortalComponent.java:127)

at com.sapportals.portal.prt.core.PortalRequestManager.callPortalComponent(PortalRequestManager.java:291)

at com.sapportals.portal.prt.core.PortalRequestManager.dispatchRequest(PortalRequestManager.java:198)

at com.sapportals.portal.prt.component.PortalComponentResponse.include(PortalComponentResponse.java:231)

at com.sapportals.portal.prt.pom.PortalNode.service(PortalNode.java:475)

at com.sapportals.portal.prt.core.PortalRequestManager.callPortalComponent(PortalRequestManager.java:291)

at com.sapportals.portal.prt.core.PortalRequestManager.dispatchRequest(PortalRequestManager.java:198)

at com.sapportals.portal.prt.core.PortalRequestManager.runRequestCycle(PortalRequestManager.java:483)

at com.sapportals.portal.prt.portalconnection.sapnative.DelegatedPlugIn.handleRequest(DelegatedPlugIn.java:725)

at com.sapportals.portal.prt.portalconnection.sapnative.PortalPlugIn.handleRequest(PortalPlugIn.java:132)

at com.sapportals.portal.prt.dispatcher.Dispatcher.service(Dispatcher.java:635)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)

at com.inqmy.services.servlets_jsp.server.InvokerServlet.service(InvokerServlet.java:126)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)

at com.inqmy.services.servlets_jsp.server.RunServlet.runSerlvet(RunServlet.java:136)

at com.inqmy.services.servlets_jsp.server.ServletsAndJspImpl.startServlet(ServletsAndJspImpl.java:789)

at com.inqmy.services.httpserver.server.RequestAnalizer.checkFilename(RequestAnalizer.java:632)

at com.inqmy.services.httpserver.server.RequestAnalizer.handle(RequestAnalizer.java:292)

at com.inqmy.services.httpserver.server.Response.handle(Response.java:165)

at com.inqmy.services.httpserver.server.HttpServerFrame.request(HttpServerFrame.java:1044)

at com.inqmy.core.service.context.container.session.ApplicationSessionMessageListener.process(ApplicationSessionMessageListener.java:36)

at com.inqmy.core.cluster.impl3.ParserRunner.run(ParserRunner.java:30)

at com.inqmy.core.thread.impl0.ActionObject.run(ActionObject.java:46)

at java.security.AccessController.doPrivileged(Native Method)

at com.inqmy.core.thread.impl0.SingleThread.run(SingleThread.java:132)