Exception: Stack is empty when using context.Forward() and AuthBot?

Question

I am following the SampleAADv2Bot example from the AuthBot tutorial. I want to authenticate my bot using an Azure Active Directory that is already configured. I set up my Web.Config with what is pictured below. I have the same code in my dialog class as listed here except my class' name is LoginDialog.cs. I see this exception in the emulator however:

The error happens when I make this call in my code (in LoginDialog.cs):

 await context.Forward(new AzureAuthDialog(AuthSettings.Scopes), this.ResumeAfterAuth, message, CancellationToken.None);

Here is my LoginDialog Class. ResumeAfterAuth() is implemented.

LoginDialog.cs:

// Copyright (c) Microsoft. All rights reserved. Licensed under the MIT 
license. See full license at the bottom of this file.
namespace Bot.Dialogs
{
    using System;
    using System.Threading;
    using System.Threading.Tasks;
    using AuthBot;
    using AuthBot.Dialogs;
    using AuthBot.Models;
    using Microsoft.Bot.Builder.Dialogs;
    using Microsoft.Bot.Connector;

    [Serializable]
    public class LoginDialog : IDialog<string>
    {
        public async Task StartAsync(IDialogContext context)
        {
            context.Wait(MessageReceivedAsync);
        }

        public async Task TokenSample(IDialogContext context)
        {
            //endpoint v2
            var accessToken = await context.GetAccessToken(AuthSettings.Scopes);

            if (string.IsNullOrEmpty(accessToken))
            {
                return;
            }

            await context.PostAsync($"Your access token is: {accessToken}");

            context.Wait(MessageReceivedAsync);
        }

        public virtual async Task MessageReceivedAsync(IDialogContext context, IAwaitable<IMessageActivity> item)
        {
            var message = await item;

            if (message.Text == "logon")
            {
                //endpoint v2
                if (string.IsNullOrEmpty(await context.GetAccessToken(AuthSettings.Scopes)))
                {
                    await context.Forward(new AzureAuthDialog(AuthSettings.Scopes), this.ResumeAfterAuth, message, CancellationToken.None);
                }
                else
                {
                    context.Wait(MessageReceivedAsync);
                }
            }
            else if (message.Text == "echo")
            {
                await context.PostAsync("echo");

                context.Wait(this.MessageReceivedAsync);
            }
            else if (message.Text == "token")
            {
                await TokenSample(context);
            }
            else if (message.Text == "logout")
            {
                await context.Logout();
                context.Wait(this.MessageReceivedAsync);
            }
            else
            {
                context.Wait(MessageReceivedAsync);
            }
        }

        private async Task ResumeAfterAuth(IDialogContext context, IAwaitable<string> result)
        {
            var message = await result;

            await context.PostAsync(message);
            context.Wait(MessageReceivedAsync);
        }
    }
}

Here is my MessagesController.cs:

namespace Bot
{
    //[BotAuthentication]
    public class MessagesController : ApiController
    {

        public async Task<HttpResponseMessage> Post([FromBody]Activity activity)
        {

            if (activity.Type == ActivityTypes.ConversationUpdate)
            {
            }
            else if (activity.Type == ActivityTypes.Message)
            {

                if (activity.Text.Contains("logon") || activity.Text.Contains("login"))
                {
                    await Conversation.SendAsync(activity, () => new Dialogs.LoginDialog());
                }
                else
                {
                    // Sends user's Id and Name to RootDialog Class
                    StateClient stateClient = activity.GetStateClient();
                    BotData userData = await stateClient.BotState.GetUserDataAsync(activity.ChannelId, activity.From.Id);
                    userData.SetProperty<string>("UserId", activity.From.Id);
                    userData.SetProperty<string>("Name", activity.From.Name);

                    // send these values in the Context
                    await stateClient.BotState.SetUserDataAsync(activity.ChannelId, activity.From.Id, userData);


                    await Conversation.SendAsync(activity, () => new Dialogs.RootDialog());
                }

            }
            else if (activity.Type == ActivityTypes.Invoke)
            {
               //...

            }
            else
            {
                HandleSystemMessage(activity);
            }
            var response = Request.CreateResponse(HttpStatusCode.OK);
            return response;
        }


    private Activity HandleSystemMessage(Activity activity)
    { 
        //...
    }

}

EDIT #1: After setting breakpoints in my code it looks like the error is happening in the WebApiConfig.cs file here:

JsonConvert.DefaultSettings = () => new JsonSerializerSettings()
{
   ContractResolver = new CamelCasePropertyNamesContractResolver(),
                Formatting = Newtonsoft.Json.Formatting.Indented,
                NullValueHandling = NullValueHandling.Ignore,
};

EDIT #2: The error happens after reaching the line shown in this picture:

When this line is reached message is null. It immediately leaves this function and goes back to the line:

await context.Forward(new AzureAuthDialog(AuthSettings.Scopes), this.ResumeAfterAuth, message, CancellationToken.None);

and then goes back to the JSON lines in WebApiConfig shown in EDIT #1, runs the function JsonSerializerSettings() twice and then the exception is thrown.

Here is the Output view of the Exception:

Answer 1

I discovered the issue. I needed to add these lines under the line GlobalConfiguration.Configure(WebApiConfig.Register); in my Global.asax.cs file:

AuthSettings.Mode = ConfigurationManager.AppSettings["ActiveDirectory.Mode"];
AuthSettings.EndpointUrl = ConfigurationManager.AppSettings["ActiveDirectory.EndpointUrl"];
AuthSettings.Tenant = ConfigurationManager.AppSettings["ActiveDirectory.Tenant"];
AuthSettings.RedirectUrl = ConfigurationManager.AppSettings["ActiveDirectory.RedirectUrl"];
AuthSettings.ClientId = ConfigurationManager.AppSettings["ActiveDirectory.ClientId"];
AuthSettings.ClientSecret = ConfigurationManager.AppSettings["ActiveDirectory.ClientSecret"];