FacebookRealtimeUpdateController Override Post and return 'OK' - asp.net-mvc

Question

Using Mvc.Facebook.Realtime the FacebookRealtimeUpdateController provides a process for handling user events (HandleUpdateAsync) , but not for page events.
Microsoft.AspNet.Mvc.Facebook.Realtime Namespace
I have managed to process page events by overriding the 'POST'
Public Overrides Function Post() As Task(Of Net.Http.HttpResponseMessage)
Dim content = Request.Content
Dim jsonContent As String = content.ReadAsStringAsync().Result
Dim ConvertedJson As RealTimeEvent = JsonConvert.DeserializeObject(Of RealTimeEvent)(jsonContent)
' Do something with the page events
Return MyBase.Post
End Function
However Facebook resends all events immediately , which I believe is because I am not returning a '200 OK' back to Facebook. (See quote)
First you'll need to prepare the page that will act as your callback URL. This URL will need to be accessible by Facebook servers, and be able to receive both the POST data that is sent when an update happens, but also accept GET requests in order to verify subscriptions.
This URL should always return a 200 OK HTTP response when invoked by Facebook.
I wiresharked my server and I do not see a 200 OK HTTP response, so I believe this something to do with the way I am overloading the post.
Can I somehow return an OK response from my overridden function or maybe it would be better to drop the whole Microsoft.AspNet.Mvc.Facebook.Realtime solution and just handle the Subscription GETs and Posts from facebook myself?
Update: I turned off "only my own code' and I can see an exception occurring in the AspNet.MVC.Facebook.dll.
So new question, How do I isolate this exception?

Answer 1

For others looking.
The issue was actually the HandleUpdateAsync function which must be overridden. This is fired after the 'Post'
If you don't return a valid task the exception is thrown inside AspNet.MVC.Facebook.dll and Facebook is never given a 200 OK.
I was using This blog on how to use the FacebookRealtimeUpdateController but in that version the 'HandleUpdateAsync' does not return a task and the processing is done in the function.
So by creating a task that does nothing , everything appears to be working fine.
Public Overrides Function HandleUpdateAsync(notification As ChangeNotification) As Task
Dim newtask As New Task(New System.Action(Sub()
Dim x As String = ""
End Sub))
Return newtask
End Function
Edit: But it creates a massive memory leak which cannot be cleared even with recycling..
So the real solution is to just create your own controller and forget the FacebookRealtimeUpdateController completely.
Very easy to do and saves allot of hassle!