The image that's supposed to show up on the "Page not found" page is missing:

Maybe it's just Chrome, but the image is sitting on a server that's different enough from stackexchange.com, it doesn't like it, when accessing the image that's supposed to be there:

https://sstatic.net/gamedev/img/404.jpg

This is what Chrome says:

Anyway, it's a minor thing, but it might happen with other things that are more important if they're similarly hosted on https://sstatic.net/gamedev/

• Happens with Safari as well.
– user1430
Jul 3, 2013 at 0:39
• Works for me on Firefox, Chromium and Luakit. The image is loading from https://cdn.sstatic.net/gamedev/img/404.jpg and I get no warnings when visiting it. The SSL cert is valid and issued by GlobalSign nv-sa on 30/05/2013.
– Anko
Jul 4, 2013 at 12:39
• I have the same issue on a default chromium, but only when following the https link given in the question. The default page image displays fine on the not found page. This site appears to be broken for https sstatic.net identifies itself as *.stackexchange.net (or so the error message tells me), and this causes the issue. Sep 22, 2013 at 13:38

Well it wasn't working for me at first, but after I went to https://sstatic.net/ it gave me that Chrome warning just like in your picture, and after I clicked proceed, it started working for me. If you read the error it says it's a server problem.

Just like with Self Signed SSL certificates, it is most likely an anti fishing protection. (Gone wrong in this case)

Here is what I get:

• Yep, I had the same experience after allowing the site.
– House Mod
Jul 3, 2013 at 13:53

This was changed to status completed and now appears to work as intended. Apparently by no longer using https.