Consider the following scenario:
Your computer is running Windows 7 or Windows Server 2008 R2.
The computer is running the Windows Communication Foundation (WCF) service, and the service is hosted on Internet Information Services (IIS). The service uses either the HTTP or the HTTPS protocol and is using Windows Authentication.
You install some Microsoft .NET Framework 3.0 Service Pack 2 or .NET Framework 3.5 Service Pack 1 updates for WCF. For example, you install security update 2756920.
In this scenario, you may receive an exception error message that resembles the following on the requested page:
Server Error in ‘/SecurtyTokenServiceApplication’ Application
Method not found: ‘System.String
For example, you may receive the error message when you go to a Microsoft SharePoint 2010 website.
When this problem occurs, you may also receive the following error message in the event log on the server:
WebHost failed to process a request.
Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/17653682
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)
This problem occurs because the computer may have some hotfixes installed that contained only System.ServiceModel.dll and not System.ServiceModel.WasHosting.dll. See the "More Information" section for a list of hotfixes that are known to contain only these files.
Because of this issue, the newer update cannot install the same version of both files. This exposes a dependency between the two files. This in turn causes the previously mentioned exception. This problem occurs because of an issue in previously released hotfixes and is not specifically caused by the new update. The new update merely causes the problem to surface.
To work around this issue, make sure that the versions of System.ServiceModel.dll and System.ServiceModel.WasHosting.dll are in sync.
To resolve this issue, install update 2637518 or any .NET Framework 3.0 SP2 hotfix that contains both assemblies.
We recommend that you install update 2637518 to resolve this issue. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.
To download this hotfix from the Microsoft Download Center, go to the following Microsoft Download Center webpage:
You may have to restart the computer after you apply this update.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
The following hotfixes can cause this issue if they are installed on a computer that is running Windows 7 or Windows Server 2008 R2 RTM and if no new .NET Framework 3.5 SP1 updates for WCF are installed. For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
976462 A hotfix for the.NET Framework 3.5 Service Pack 1 is available for Windows 7 and for Windows Server 2008 R2 as a prerequisite for Microsoft Office SharePoint Server 2010
977420 A hotfix rollup is available to fix problems in Windows Communication Foundation in the .NET Framework 3.5 SP1 for Windows 7 and for Windows Server 2008 R2
982867 WCF services that are hosted by computers together with a NLB fail in the .NET Framework 3.5 SP1 or in the .NET Framework 4