iWeb RSS feed will not load with any site.

I am trying to display an simple RSS feed on my website and what ever site l use, BBC, France24, ABC, FOX News etc... whenever l copy and paste the RSS link in the widget and click apply. I am shown the message "The RSS feed source can't be reached. Try again."

Here is an example of how i'm inputing the RSS link:

feed://feeds.bbci.co.uk/news/uk/rss.xml

feed://www.france24.com/en/france/rss/

Your help is much appreciated. Thanks