ASP.NET 5/Core/vNext CORS not working even if allowing pretty much everything

Question

I have a ASP.NET 5 Web API (Well, MVC now anyway) back-end which I am consuming in with the axios library in my JS app.

My CORS config in MVC is the following:

Answer 1

If you're using UseHttpsRedirection, make sure your app is calling the https URL and not the http one or you'll get a CORS error even though the Accept-Header-Allow-Origin header is returned.