Welcome to the forums.
If you're referring to the error under your username in the posts (this one: [CaRP]
XML error: This appears to be an HTML webpage, not a feed)
It's because you have incorrectly typed in the RSS feed for your blog. You need to put the exact url of your RSS feed in to get the link to your latest blog post. Otherwise you'll just get an error message like the one above.
Hope that helps
Vicky