nao sei como corrigir este erro… 
Grave: Error Rendering View[/jsp/Restrito/Cliente/Menu.xhtml]
java.lang.NullPointerException
at org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:184)
at com.sun.faces.application.view.WriteBehindStateWriter.write(WriteBehindStateWriter.java:127)
at com.sun.faces.renderkit.html_basic.HtmlResponseWriter.write(HtmlResponseWriter.java:666)
at org.primefaces.component.tabview.TabViewRenderer.encodeTabHeader(TabViewRenderer.java:207)
at org.primefaces.component.tabview.TabViewRenderer.encodeHeaders(TabViewRenderer.java:161)
at org.primefaces.component.tabview.TabViewRenderer.encodeMarkup(TabViewRenderer.java:127)
at org.primefaces.component.tabview.TabViewRenderer.encodeEnd(TabViewRenderer.java:69)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:884)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1659)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:854)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1652)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1655)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:399)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:509)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Abr 04, 2012 12:27:31 PM org.apache.catalina.core.StandardWrapperValve invoke
Grave: Servlet.service() for servlet [Faces Servlet] in context with path [/Projeto] threw exception [null] with root cause
java.lang.NullPointerException
at org.apache.catalina.connector.CoyoteWriter.write(CoyoteWriter.java:184)
at com.sun.faces.application.view.WriteBehindStateWriter.write(WriteBehindStateWriter.java:127)
at com.sun.faces.renderkit.html_basic.HtmlResponseWriter.write(HtmlResponseWriter.java:666)
at org.primefaces.component.tabview.TabViewRenderer.encodeTabHeader(TabViewRenderer.java:207)
at org.primefaces.component.tabview.TabViewRenderer.encodeHeaders(TabViewRenderer.java:161)
at org.primefaces.component.tabview.TabViewRenderer.encodeMarkup(TabViewRenderer.java:127)
at org.primefaces.component.tabview.TabViewRenderer.encodeEnd(TabViewRenderer.java:69)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:884)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1659)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:854)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1652)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1655)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:399)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:509)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)