at DotNetOpenAuth.Messaging.StandardWebRequestHandler.GetResponse(HttpWebRequest request, DirectWebRequestOptions options)
   at DotNetOpenAuth.Messaging.Channel.RequestCore(IDirectedProtocolMessage request)
   at DotNetOpenAuth.Messaging.Channel.Request(IDirectedProtocolMessage requestMessage)
   at DotNetOpenAuth.Messaging.Channel.Request[TResponse](IDirectedProtocolMessage requestMessage)
   at DotNetOpenAuth.OAuth.ConsumerBase.PrepareRequestUserAuthorization(Uri callback, IDictionary`2 requestParameters, IDictionary`2 redirectParameters, String& requestToken)
   at DotNetOpenAuth.AspNet.Clients.DotNetOpenAuthWebConsumer.RequestAuthentication(Uri callback)
   at BusinessInternational.Controllers.SocialController.LinkedIn(String oauth_token) in C:\PROGETTI\BusinessInternational\BusinessInternational\Controllers\SocialController.cs:line 141