Microsoft released KB2756920 (Windows Server 2008 R2) and KB2756921 (Windows Server 2008 R2 SP1) security patches on January 08. 2013. After the installation lot of Service Applications just stopped working. I had a problem reported with Excel Services Service Application so I started digging through ULS logs. The exception I found wasn’t really informative:

01/22/2013 15:30:43.08  w3wp.exe (0x32A4) 0x20A0 Excel Services Application   Web Front End 5240  Critical  There was an error in communicating with Excel Calculation Services http://srvsp03:32843/806754664b1f4c06a45f19fb79495599/AccessService.svc exception: Fehler [Session: User: CONTOSO\spfarmapp]

I turned on exception details for Access Service web service and tried to open the service URL in browser. Then I got the following exception:

System.InvalidOperationException: An exception was thrown in a call to a policy export extension.
Extension: System.ServiceModel.Channels.TransportSecurityBindingElement
Error: Security policy export failed. The binding contains a TransportSecurityBindingElement but no transport binding element that implements ITransportTokenAssertionProvider. Policy export for such a binding is not supported. Make sure the transport binding element in the binding implements the ITransportTokenAssertionProvider interface. —-> System.InvalidOperationException: Security policy export failed. The binding contains a TransportSecurityBindingElement but no transport binding element that implements ITransportTokenAssertionProvider. Policy export for such a binding is not supported. Make sure the transport binding element in the binding implements the ITransportTokenAssertionProvider interface.
   at System.ServiceModel.Channels.TransportSecurityBindingElement.
System.ServiceModel.Description.IPolicyExportExtension.ExportPolicy(MetadataExporter exporter, PolicyConversionContext policyContext)
   at System.ServiceModel.Description.MetadataExporter.ExportPolicy(ServiceEndpoint endpoint)

I am not sure what is introduced in these patches but if I had to guess, I would say that security got tightened too much. The fact is that these patches broke my services (and will break yours if you install them). So, I removed the patch, restarted the server and everything was working again.