Crawl error for URLs that never existed

My page as created and submitted on my sitemap is http://carolinaseminars.com/home-2/ but I am receiving crawl error referring to http://carolinaseminars.com/home-2/seminars/building-seminars/ , which doesn’t exist/NEVER existed. I have over 260 crawl errors where this seminars/building-seminars/ is added to the URLs I have submitted on my sitemap. Does this have anything to do with the theme?