After installing jenkis, I am getting the following exception. It seems that the server certificate has expired.

Attempting to reconnect slave
2 27, 2014 9:57:02 午後 致命的 hudson.model.DownloadService$Downloadable doPostBack
Signature verification failed in downloadable 'hudson.tools.JDKInstaller'
java.security.cert.CertPathValidatorException: timestamp check failed
at sun.security.provider.certpath.PKIXMasterCertPathValidator.validate(PKIXMasterCertPathValidator.java:139)
at sun.security.provider.certpath.PKIXCertPathValidator.doValidate(PKIXCertPathValidator.java:330)
at sun.security.provider.certpath.PKIXCertPathValidator.engineValidate(PKIXCertPathValidator.java:178)
at java.security.cert.CertPathValidator.validate(CertPathValidator.java:250)
at org.jvnet.hudson.crypto.CertificateUtil.validatePath(CertificateUtil.java:93)
at jenkins.util.JSONSignatureValidator.verifySignature(JSONSignatureValidator.java:92)
at hudson.model.DownloadService$Downloadable.doPostBack(DownloadService.java:258)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:298)
at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:161)
at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:96)
at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:120)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:728)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:858)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:248)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:728)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:858)
at org.kohsuke.stapler.MetaClass$12.dispatch(MetaClass.java:390)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:728)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:858)
at org.kohsuke.stapler.MetaClass$4.doDispatch(MetaClass.java:210)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:728)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:858)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:631)
at org.kohsuke.stapler.Stapler.service(Stapler.java:225)
at javax.servlet.http.HttpServlet.service(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Source)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:96)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:203)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:181)
at net.bull.javamelody.PluginMonitoringFilter.doFilter(PluginMonitoringFilter.java:86)
at org.jvnet.hudson.plugins.monitoring.HudsonMonitoringFilter.doFilter(HudsonMonitoringFilter.java:90)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:99)
at com.cloudbees.jenkins.support.SupportMetricsFilter.doFilter(SupportMetricsFilter.java:105)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:99)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:88)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Source)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:48)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Source)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
at hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:51)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at jenkins.security.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:117)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:142)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:174)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at jenkins.security.ApiTokenFilter.doFilter(ApiTokenFilter.java:64)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:67)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Source)
at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:46)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Source)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Source)
at org.apache.catalina.core.StandardWrapperValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardContextValve.invoke(Unknown Source)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(Unknown Source)
at org.apache.catalina.core.StandardHostValve.invoke(Unknown Source)
at org.apache.catalina.valves.ErrorReportValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardEngineValve.invoke(Unknown Source)
at org.apache.catalina.connector.CoyoteAdapter.service(Unknown Source)
at org.apache.coyote.ajp.AjpAprProcessor.process(Unknown Source)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(Unknown Source)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.security.cert.CertificateExpiredException: NotAfter: Thu Feb 27 04:21:29 JST 2014
at sun.security.x509.CertificateValidity.valid(CertificateValidity.java:256)
at sun.security.x509.X509CertImpl.checkValidity(X509CertImpl.java:568)
at sun.security.provider.certpath.BasicChecker.verifyTimestamp(BasicChecker.java:157)
at sun.security.provider.certpath.BasicChecker.check(BasicChecker.java:109)
at sun.security.provider.certpath.PKIXMasterCertPathValidator.validate(PKIXMasterCertPathValidator.java:117)
... 88 more