Hi, on http://www.sekcijamladih.org I create RSS feed reader into home page to display blog post in , but 5 days after massage in box is *url: "http://www.sekcijamladih.org/blog/x5feed.xml" error: host site not found* ???

I chack /blog folder, .xml file is thare, but ....nothing!!? 

What is this, how to solve this fast, I provide this site for client and must to solve this now !!

Thanks in advance ! I waiting for your help...