User blog comment:Brandon Rhea/Wiki Modernization: New Ad Layout is Now Live/@comment-32094204-20171005191017/@comment-20644-20171006002955

Thanks for clarifying. The issue was that you didn't have all of the main page column tags you need for the main page to work properly. You had a closing tag for the right-hand column, but not an opening tag. I've fixed that for you, and you can see the fix here.