Why is a "You'll need a new app to open this localhost" popup being displayed when debugging my asp.net core 2.0 app in Edge?

Question

I'm simply entering "MyMessages/Index" after localhost:51531/ and this popup is being displayed. Seems super weird to me but probably something simple.

So I try to navigate to localhost:51531/MyMessages/Index in Edge.

The controller is public class MyMessagesController : Controller

The controller action is just:

public IActionResult Index()
{
    return View();
}

Any idea why this is happening?

This does not happen in IE11

Answer 1

The issue is that you have left the scheme off the start of the URL. Some browsers will infer it in certain circumstances, but not all browsers will infer it all the time.

Instead of:

localhost:51531/MyMessages/Index

Try:

http://localhost:51531/MyMessages/Index