var response = await base.SendAsync(request, cancellationToken);
 
        if (credentials == null && response.StatusCode == HttpStatusCode.Unauthorized)
                Challenge(request, response);
 
 
        return response;

        return base.SendAsync(request, cancellationToken)
            .ContinueWith(task =>
            {
                var response = task.Result;
                if (credentials == null && response.StatusCode == HttpStatusCode.Unauthorized)
                    Challenge(request, response);
 
 
                return response;
            });

 RazorEngineFactory<TBaseTemplateType>.UnloadRazorHostInAppDomain();

            config.Routes.MapHttpRoute(
                name: "ActionApi",
                routeTemplate: "calc/{controller}/{action}",
                defaults: new 
                { controller = "MWM",
                  action = "CalcMWM"                                  
                }
            );

    <httpProtocol>
      <customHeaders>
        <add name="Access-Control-Allow-Origin" value="*" />
        <add name="Access-Control-Allow-Headers" value="Origin, X-Requested-With, Content-Type, Accept" />
      </customHeaders>
    </httpProtocol>