I am constantly getting this error when I try to upload a page with a web content overlay -- i even get thi smessage if i try to upload http://google.com.
This link is likely being redirected, and redirects aren't allowed in Web Content overlays. For example, http://www.google.com will work, but http://google.com won't. Check the URL on a mobile device. A lot of sites get redirected to the mobile version: http://twitter.com becomes http://mobile.twitter.com.
Europe, Middle East and Africa