Wordpress Blog Error

When I click on the button where you can find your xml sitemap it opens a new tab and say 404 Not Found nginx. You can see it here:
<a href="http://www.searchmydegree.com/">http://www.searchmydegree.com/</a>

<a href="http://www.ultimatedollarclicks.com">http://www.ultimatedollarclicks.com</a> i am getting error in both

using this plugin

' target='_blank' rel='nofollow'>http://wordpress.org/extend/plugins/wordpress-seo/</code>