This sounds similar to the thread: http://social.technet.microsoft.com/Forums/sharepoint/en-US/903d0e22-6419-48c5-8669-a1191c841b76/after-security-update-kb2756920-problems-in-sharepoint-2010
But started after updates installed on 8/15/2013. I have not tried to figure out which update may have done it as there were quite a few of them that night and it doesn't seem to be directly affecting what I am using the server for. The server is 2008R2 Enterprise SP1 running stand alone with TFS 2010/SharePoint 2010/SQL Server 2008R2 for a very small software development group.
Any ideas how to get rid of the error??
The first error looks like this:
WebHost failed to process a request.
Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/34106743
Exception: System.ServiceModel.ServiceActivationException: The service '/7a8d64250ff948689970b460de055267/PerformancePointService.svc' cannot be activated due to an exception during compilation. The exception message is: Loading this assembly would produce a different grant set from other instances. (Exception from HRESULT: 0x80131401). ---> System.IO.FileLoadException: Loading this assembly would produce a different grant set from other instances. (Exception from HRESULT: 0x80131401)
at System.Enum.InternalBoxEnum(Type enumType, Int64 value)
at System.Enum.GetValues(Type enumType)
at Microsoft.SharePoint.Administration.SPAutoSerializingObject.DeserializeBasicObject(XmlElement xmlValue, Boolean isMerge, Boolean bResolveMissingTypes)
at Microsoft.SharePoint.Administration.SPAutoSerializingObject.DeserializeBasicObject(XmlElement xmlValue, Boolean isMerge, Boolean bResolveMissingTypes)
at Microsoft.SharePoint.Administration.SPAutoSerializingObject.SetStateXml(XmlNodeList childNodes, Boolean isMerge, Boolean bResolveMissingTypes)
at Microsoft.SharePoint.Administration.SPAutoSerializingObject.SetStateXml(XmlDocument value, Boolean bResolveMissingTypes)
at Microsoft.SharePoint.Administration.SPPersistedObject.Initialize(ISPPersistedStoreProvider persistedStoreProvider, Guid id, Guid parentId, String name, SPObjectStatus status, Int64 version, XmlDocument state)
at Microsoft.SharePoint.Administration.SPFileSystemCache.FetchObjectFromFileSystem(Guid id)
at Microsoft.SharePoint.Administration.SPFileSystemCache.GetValue(Guid id)
at Microsoft.SharePoint.Administration.SPCache`2.get_Item(K key)
at Microsoft.SharePoint.Administration.SPConfigurationDatabase.GetObject(Guid id, Boolean checkInMemoryCache, Boolean checkFileSystemCache)
at Microsoft.SharePoint.Administration.SPServiceApplication.get_Current()
at Microsoft.SharePoint.SPServiceHostOperations.Configure(ServiceHostBase serviceHost, SPServiceAuthenticationMode authenticationMode)
at Microsoft.PerformancePoint.Scorecards.BIMonitoringServiceHostFactory.CreateServiceHost(String constructorString, Uri[] baseAddresses)
at System.ServiceModel.ServiceHostingEnvironment.HostingManager.CreateService(String normalizedVirtualPath)
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: 8140