javax.faces.application.ViewExpiredException：无法恢复视图

我用jsf，prettyfaces和hibernate创建了这个网页我环顾四周，大多数人都说这个错误是因为缓存他们中的大多数人在登录，注销并尝试登录后发现此错误但我登录时发现此错误，当我尝试导航到任何其他页面时，我点击的任何链接都会产生此错误更难的是每次都不会发生这种错误有时当我尝试重新启动服务器，登录回来时，每个工作都很好但有时当再次出现此错误时，我尝试重新启动服务器并尝试重新登录。仍然会出现相同的错误

javax.faces.application.ViewExpiredException: viewId:/ePortfolio.jsf - View /ePortfolio.jsf could not be restored.
at com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:212)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:110)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:312)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.ocpsoft.pretty.PrettyFilter.doFilter(PrettyFilter.java:112)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:470)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)