RSS feeds not readable by browsers
 

I've set an RSS feed on my website (through External Data Providers in the General settings). An RSS icon becomes visible in the title bar. But when I click it, I see the error message "Can't open 'feed://forums.techlifezone.com/external.php?type=RSS2' . Error: The channel can't be loaded, because it has an unknown channel structure.' (PubSub:2)"

When I try it in Firefox, it just shows an empty page.

Did I do something wrong? I also tried XML, but that results in the error message "Can't find source file

Just to add, it's not a sudden issue. I never had RSS working on my website.