Failed to download metadata from /Shibboleth.sso/DiscoFeed

[Peter Schober]

* Anon Programmer <anonprogrammerr at gmail.com> [2017-12-13 23:14]:
> I changed it to:
> this.dataSource = 'https://<my-ip>/Shibboleth.sso/DiscoFeed';
> 
> Same error.

What happens if you run this command on the server housing the SP?
$ curl -sk https://localhost/Shibboleth.sso/DiscoFeed

Or whatever schema and port the webserver listens on, locally.
-peter