An empty page answers with status 200, so the address works, but the server sends back no content at all. Visitors see a white screen.
Google has nothing to index and treats the page as broken. If the address is in your sitemap or in the menu, you send visitors and Google to a dead end that does not even look like an error.
Snaglist reads the HTML of every page that answers with 200. A page whose HTML is empty, or only contains comments, is listed once as an empty page instead of as a page without title, description and H1.
Snaglist runs this check and 43 others on every page of your site, every week. 14 days free, no credit card needed.
Try free for 14 days