Why are my browsers saying one specific meta page is "not secure"?

Question

I tried to browse following this link https://meta.languagelearning.stackexchange.com/questions/231/create-an-ad-for-this-site but Firefox gives me:

Websites prove their identity via certificates. Firefox does not trust this site because it uses a certificate that is not valid for meta.languagelearning.stackexchange.com. The certificate is only valid for the following names: *.askubuntu.com, *.blogoverflow.com, *.mathoverflow.net, *.meta.stackexchange.com, *.meta.stackoverflow.com, *.serverfault.com, *.sstatic.net, *.stackexchange.com, *.stackoverflow.com, *.stackoverflow.email, *.superuser.com, askubuntu.com, blogoverflow.com, mathoverflow.net, openid.stackauth.com, serverfault.com, sstatic.net, stackapps.com, stackauth.com, stackexchange.com, stackoverflow.blog, stackoverflow.com, stackoverflow.email, stacksnippets.net, superuser.com

I switched to Chromium, and it gives:

This server could not prove that it is meta.languagelearning.stackexchange.com; its security certificate is from *.stackexchange.com. This may be caused by a misconfiguration or an attacker intercepting your connection.

It doesn't show this warning/error for other meta pages (in fact, I don't recall ever seeing this warning at any other Stack Exchange page), just this one. I can access the page if I click "Accept the Risk and Continue".

Question: Why are my browsers saying one specific meta page is "not secure"?

I'm not sure if this is important. It seems like a bug of some kind.

Answer 1

At some point in the past, all meta sites were moved. Originally, they had URLs like meta.sitename.stackexchange.com. Now they are hosted under Meta: sitename.meta.stackexchange.com.

No automatic redirect is in place, so you need to manually rewrite the old URLs to switch "meta" and the sitename around, in order to get a working URL.

So you need to rewrite https://meta.languagelearning.stackexchange.com/questions/231/create-an-ad-for-this-site into https://languagelearning.meta.stackexchange.com/questions/231/create-an-ad-for-this-site, which works fine.