Bot Emulator Says Couldn't Send Retry

Hi,

I am new to Microsoft Bot Framework.
I created my first bot application by using bot application template on Visual Studio 2015. it is running fine and below is the message I get when i run this.

Describe your bot here and your terms of use etc.

Visit Bot Framework to register your bot. When you register it, remember to set your bot's endpoint to

https://your_bots_hostname/api/messages.

And I have downloaded botframework-emulator 3.5.29 and installed. On the emulator i have entered http://localhost:3979/api/messages/ and left the App Id & App Password fields as empty. everything was looks fine. But when i type any message on the emulator I am getting Couldn't send retry notification on emulator.

Please can anyone help me on this.

Thanks,