[Error] Unknown news site [How to fix] Check that the URL of your Sitemap agrees with the URLs of your articles as they appear on Google News, including any leading "www". If you would like to request inclusion of your site in Google News, please apply for inclusion within the Google News Publisher Center. [Description] 
Your Sitemap is on a site that is not in the Google News database. Google News can only accept Sitemaps from sites that we crawl.