Unable to start debugging on the web server. Unable to connect to the web server. Verify that the web server is running and that incoming HTTP requests are not blocked by a firewall.

One of the very common error message you will get when you try to run or debug your ASP.NET web application or website.

Unable to start debugging on the web server. Unable to connect to the web server. Verify that the web server is running and that incoming HTTP requests are not blocked by a firewall.

One can check following items on his development environment: