ASP.NET MVC 4 error with Google CalendarAPIv3

I try this:

var auth = new AuthorizationCodeMvcApp(controller, 
                                       new FlowMetaDataCalendarV3())
           .AuthorizeAsync(CancellationToken.None).Result;

AuthorizationCodeMvcApp execute fine, but AuthorizeAsync throw a exception in NewtonSoft.Json:

[NewtonSoft.Json.JsonreaderException] --> {"Error reading JObject from JsonReader. Current JsonReader item is not an object: String. Path '', line 1, position 72."}

I currently installed:
Google.Apis.Auth vrs 1.9.0
Google.Apis.Auth.MVC 1.9.0
NewtonSoft.Json 6.0.4

How to resolve this??