Unable to delete messages in Outlook Web Access (OWA) after installing the KB2756920 hotfix

After the last automatic updates from Microsoft, installed in January 2013 the Outlook Web Access (OWA) interface seems to be broken. When trying to delete messages this message is shown: “An unexpected error occurred and your request couldn’t be handled.”.

After further debugging the error seems to originate from the exchange webservice: /EWS/exchange.asmx and this is the error message logged in the event log:

WebHost failed to process a request.
 Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/32001227
 Exception: System.ServiceModel.ServiceActivationException: The service '/Autodiscover/autodiscover.xml' 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.HttpsChannelListener.ApplyHostedContext(VirtualPathExtension virtualPathExtension, Boolean isMetadataListener)
   at System.ServiceModel.Channels.HttpsTransportBindingElement.BuildChannelListener[TChannel](BindingContext context)
   at System.ServiceModel.Channels.BindingContext.BuildInnerChannelListener[TChannel]()
   at System.ServiceModel.Channels.BindingElement.BuildChannelListener[TChannel](BindingContext context)
   at Microsoft.Exchange.Autodiscover.WCF.LegacyMessageEncoderBindingElement.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 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: 1516

To fix the issue, simply install KB981002 and restart the server. It’s an old hotfix and I don’t have details on how the hotfix solves the issue.

Download the hotfix (KB981002)