Articles: Ops…page not found

Hi, I'm facing problems publishing articles with my Catch Everest theme. I write, save and publish the article, it goes into the published articles list, it is present and readable into the Archive, but if you recall it from the slider in the homepage the site says "Ops...Page not Found". I have no strange plugins installed, and I am sure that the MySql database works and it is properly set. At the moment, the site works fine but only publishing pages, and not articles. Can you help me? Erminio Ramponi www.oasicervara.it