No problem. I'll leave the post because there's more to the story actually
Yes, as you know, your site is actually unreachable. However, when you go live with your site, you still may see this issue initially as Facebook doesn't scan the page immediately. Additionally, if you have pages that are for registered users only (which would prevent Facebook from scanning them), you may also initially see this error too. However, as Facebook scans other public pages, and more users see the 'private' pages, Facebook will eventually just start trusting that the page exists and stop giving that error for any pages, even if they are restricted.
Hope that helps, and makes sense,
Alex