昨天公司的SharePoint Server被自动安装了补丁KB2756920后，出现了如下现象：
- 无法访问任何站点，报503 server error
- 在Event log在出现错误：
Event ID: 3
Source: System.ServiceModel 3.0.0.0
Detail:
WebHost failed to process a request.
Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/37916227
Exception: System.ServiceModel.ServiceActivationException: The service '/SecurityTokenServiceApplication/securitytoken.svc' cannot be activated due to an exception during compilation. The exception message is: Method not found: 'System.String System.ServiceModel.Activation.Iis7Helper.ExtendedProtectionDotlessSpnNotEnabledThrowHelper(System.Object)'.. ---> System.MissingMethodException: Method not found: 'System.String System.ServiceModel.Activation.Iis7Helper.ExtendedProtectionDotlessSpnNotEnabledThrowHelper(System.Object)'.
at System.ServiceModel.WasHosting.MetabaseSettingsIis7V2.WebConfigurationManagerWrapper.BuildExtendedProtectionPolicy(ExtendedProtectionTokenChecking tokenChecking, ExtendedProtectionFlags flags, List`1 spnList)
at System.ServiceModel.WasHosting.MetabaseSettingsIis7V2.WebConfigurationManagerWrapper.GetExtendedProtectionPolicy(ConfigurationElement element)
at System.ServiceModel.WasHosting.MetabaseSettingsIis7V2.ProcessWindowsAuthentication(String siteName, String virtualPath, HostedServiceTransportSettings& transportSettings)
at System.ServiceModel.WasHosting.MetabaseSettingsIis7V2.CreateTransportSettings(String relativeVirtualPath)
at System.ServiceModel.Activation.MetabaseSettingsIis.GetTransportSettings(String virtualPath)
at System.ServiceModel.Activation.MetabaseSettingsIis.GetAuthenticationSchemes(String virtualPath)
at System.ServiceModel.Channels.HttpChannelListener.ApplyHostedContext(VirtualPathExtension virtualPathExtension, Boolean isMetadataListener)
at System.ServiceModel.Channels.HttpTransportBindingElement.BuildChannelListener[TChannel](BindingContext context)
at System.ServiceModel.Channels.BindingContext.BuildInnerChannelListener[TChannel]()
at System.ServiceModel.Channels.MessageEncodingBindingElement.InternalBuildChannelListener[TChannel](BindingContext context)
at System.ServiceModel.Channels.BinaryMessageEncodingBindingElement.BuildChannelListener[TChannel](BindingContext context)
at System.ServiceModel.Channels.BindingContext.BuildInnerChannelListener[TChannel]()
at System.ServiceModel.Channels.Binding.BuildChannelListener[TChannel](Uri listenUriBaseAddress, String listenUriRelativeAddress, ListenUriMode listenUriMode, BindingParameterCollection parameters)
at System.ServiceModel.Description.DispatcherBuilder.MaybeCreateListener(Boolean actuallyCreate, Type[] supportedChannels, Binding binding, BindingParameterCollection parameters, Uri listenUriBaseAddress, String listenUriRelativeAddress, ListenUriMode listenUriMode, ServiceThrottle throttle, IChannelListener& result, Boolean supportContextSession)
at System.ServiceModel.Description.DispatcherBuilder.BuildChannelListener(StuffPerListenUriInfo stuff, ServiceHostBase serviceHost, Uri listenUri, ListenUriMode listenUriMode, Boolean supportContextSession, IChannelListener& result)
at System.ServiceModel.Description.DispatcherBuilder.InitializeServiceHost(ServiceDescription description, ServiceHostBase serviceHost)
at System.ServiceModel.ServiceHostBase.InitializeRuntime()
at Microsoft.IdentityModel.Protocols.WSTrust.WSTrustServiceHost.InitializeRuntime()
at System.ServiceModel.ServiceHostBase.OnOpen(TimeSpan timeout)
at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
at System.ServiceModel.ServiceHostingEnvironment.HostingManager.ActivateService(String normalizedVirtualPath)
at System.ServiceModel.ServiceHostingEnvironment.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath)
--- End of inner exception stack trace ---
at System.ServiceModel.ServiceHostingEnvironment.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath)
at System.ServiceModel.ServiceHostingEnvironment.EnsureServiceAvailableFast(String relativeVirtualPath)
Process Name: w3wp
Process ID: 7120
解决方案： 卸载KB2756920，并重启服务器
参考：http://blogs.technet.com/b/steve_chen/archive/2013/01/11/3545423.aspx