c# - ServiceActivationException: Request cannot be dispatched because the virtual application is shutting down -

There is a problem closing our virtual applications. I Site ASP.NET 4.5 is running

Exception Summary:

  System. Translation Operation Exception: '/ s services / serviceexceptionlogger can not be sent to request' Svc 'because' / site ' Closing virtual application  

Stack trace:

  System. Servicemodel. Service Activation Exception: 'Request for service' on '/ services / ServiceExceptionLogger.svc' can not be postponed because the virtual application is shutting down on '/ site'. --- & gt; System.InvalidOperationException: The request for service to '~ / services / ServiceExceptionLogger.svc' can not be sent because the virtual application is shutting down on '/ site'. --- Internal exception stack trace in the system --- Android On the system System (service).  
  Stack trace:   
  
 Code> system Servicemodel. Service Activation Exception: The request for service to '/ / services / service.svc' can not be sent because the virtual application is shutting down on '/ site'. --- & gt; System.InvalidOperationException: The request for the service can not be sent on '~ / Services / Service.svc' because the virtual application is shutting down on '/ Site'. --- Internal exception stack trace in the system --- Android On the system System (service). OnAsyncHandler closing (IAsyncResult AR)  
 
 Has anyone seen this before or any idea? It seems that once in our environment this happens, like 10 + times in the day. This is not happening at the QA environment at all. Passive environments are set for 20 minutes on both environments, the reason for termination of 20 minutes is to avoid wasted memory 
 
 Update 1: There are some supplemental information on locking the AP Pool 
 
 Update 2: App Pool is not recycling apparently when the exception is above we are looking at the process in the task manager and this exception occurs when the memory is not being shut down or is being reduced. Also, after increasing it to support Microsoft, there is no entry entry (see Update 1) when this exception occurs 
 

, we think this problem is a bug. NET 4.5.1 This is most likely when running in integrated mode, but it is also in classic mode, although very often it is often We are not able to solve the real case or problem, but it does not appear on the old NAT Runtime.