You may not call this function on a different context than the original request at:    at Microsoft.TeamFoundation.Framework.Server.TeamFoundationRequestContext.GetService[T]()
   at Microsoft.TeamFoundation.Server.Core.ProxyStatistics.ScanDisk(Object stateInfo)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()