Error: Stack is empty exception in Bot Framework

Question

Hi, I created a chatbot by Bot Framework and I implemented a Reset option in order to delete the conversation e grant to the user to begin a new conversation. // MessageController.cs public async Task Post([FromBody]Activity activity) { await Conversation.SendAsync(activity, () => new RootDialog().DefaultIfException()); return Request.CreateResponse(HttpStatusCode.OK); } // RootDialog.cs private void ShowMenuOptions(IDialogContext context) { List string > optionList = new List string >(); optionList.Add( "Info" ); optionList.Add( "Support" ); optionList.Add( "Reset" ); string prompt = "How can I help you?" ; PromptDialog.Choice(context, this .OnOptionSelected, (IEnumerable string >)optionList, prompt, retry, attempts); } private async Task OnOptionSelected(IDialogContext context, IAwaitable string > result) { try { string optionSelected = await result; switch (optionSelected) { case "Reset" : context.Reset(); context.ConversationData.Clear(); context.PrivateConversationData.Clear(); context.UserData.Clear(); break ; } } } When an user chooses reset option, the bot answers with "Sorry, my bot code is having an issue." Debugging the code I see that the exception triggers after context.Reset(). Can anybody help me and solve it?

Emanuele Leoni · Answer

I solved it implementing global Reset message handler. First of all I created a new CancelScorable public class CancelScorable : ScorableBase string , double > { private readonly IDialogTask task; private readonly IBotData botData; public CancelScorable(IDialogTask task, IBotData botData) { SetField.NotNull( out this .task, nameof(task), task); SetField.NotNull( out this .botData, nameof(botData), botData); } protected override async Task string > PrepareAsync(IActivity activity, CancellationToken token) { var message = activity as IMessageActivity; if (message != null && ! string .IsNullOrWhiteSpace(message.Text)) { if (message.Text.Equals( "reset" , StringComparison.InvariantCultureIgnoreCase)) { return message.Text; } } return null ; } protected override bool HasScore(IActivity item, string state) { return state != null ; } protected override double GetScore(IActivity item, string state) { return 1.0; } protected override async Task PostAsync(IActivity item, string state, CancellationToken token) { this .task.Reset(); botData.UserData.Clear(); botData.PrivateConversationData.Clear(); await botData.FlushAsync(token); } protected override Task DoneAsync(IActivity item, string state, CancellationToken token) { return Task.CompletedTask; } } Then I create GlobalMessageHandlersBotModule public class GlobalMessageHandlersBotModule : Module { protected override void Load(ContainerBuilder builder) { base .Load(builder); builder .Register(c => new CancelScorable(c.Resolve (), c.Resolve ())) .As double >>() .InstancePerLifetimeScope(); } } At last I registried in GlobalAsax protected void Application_Start() { this .RegisterBotModules(); GlobalConfiguration.Configure(WebApiConfig.Register); } private void RegisterBotModules() { var builder = new ContainerBuilder(); builder.RegisterModule( new ReflectionSurrogateModule()); builder.RegisterModule (); builder.Update(Conversation.Container); } I hope this can help you!