BOT Framework emulator stopped rendering HTML

Bot Framework suddenly stopped rendering html, I have attached screenshot. What can be wrong? I am using v3.5.31 which is the latest one. I have used Bot Application template which is bydefault available when creating new BOT project.

Below is the code i have written

[Serializable]
    public class RootDialog : IDialog<object>
    {
        public Task StartAsync(IDialogContext context)
        {
            context.Wait(MessageReceivedAsync);

            return Task.CompletedTask;
        }

        private async Task MessageReceivedAsync(IDialogContext context, IAwaitable<object> result)
        {
            PromptDialog.Text(context, resumeAfter, "Enter your name", "Didn't get that",
                      3
                      );
        }

        private async Task resumeAfter(IDialogContext context, IAwaitable<string> result)
        {
            string answer = await result;
            await context.PostAsync($"Hello <i><b>{answer}</b></i>");
        }
    }