I have a problem similar to others posted, but with a different error detail and I have tried most of the fixes listed in the other posts with no success.
We just performed an in-place upgrade from SP2007 to SP2010 standard. We are using Kerberos authentication in a two server farm, both servers are Windows 2008 SP2. Immediately after the upgrade, the subject error message appeared in Central Admin. When I try to navigate to http://localhost:32843/SecurityTokenServiceApplication/securitytoken.svc, I get the following Error and Stack Trace...any help will be GREATLY appreciated.
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
[MethodAccessException: Microsoft.SharePoint.IdentityModel.SPSecurityTokenServiceHostFactory..ctor()]
System.Reflection.MethodBase.PerformSecurityCheck(Object obj, RuntimeMethodHandle method, IntPtr parent, UInt32 invocationFlags) +0
System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +396
System.ServiceModel.HostingManager.CreateService(String normalizedVirtualPath) +577
System.ServiceModel.HostingManager.ActivateService(String normalizedVirtualPath) +46
System.ServiceModel.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath) +654
[ServiceActivationException: The service '/SecurityTokenServiceApplication/securitytoken.svc' cannot be activated due to an exception during compilation. The exception message is: Microsoft.SharePoint.IdentityModel.SPSecurityTokenServiceHostFactory..ctor().]
System.ServiceModel.AsyncResult.End(IAsyncResult result) +15779952
System.ServiceModel.Activation.HostedHttpRequestAsyncResult.End(IAsyncResult result) +15701001
System.Web.AsyncEventExecutionStep.OnAsyncEventCompletion(IAsyncResult ar) +101
Bill Tibbetts, IT Engineer