​After setting up and using Web Deployment from Visual Studio 2013 many many times, I experienced an error:

Error 79 Web deployment task failed. (Web Deploy experienced a connection problem with the server and had to terminate the connection. Contact your server administrator if the problem persists. Learn more at: http://go.microsoft.com/fwlink/?LinkId=221672#ERROR_CONNECTION_TERMINATED.)

I couldn’t figure out why this error suddently started occuring. I evnet rebooting my development server as I thought it hosted the problem.

It turns out it was as simple as FIDDLER being active. Once I closed fiddler web deploy worked without issue.