I use primarily the Yahoo OpenId sign in option for my StackOverflow account. Typically, I spend way more time on SO than meta (meaning I rarely have to re-login on SO). When I switch from SO to meta, I usually always get the "You have been logged in - click here to refresh message". Tonight I am not getting that message. Additionally, when I attempt to login with the yahoo endpoint in either meta or SO (by clicking on the more options, then the Yahoo! icon), I receive the following message (after a 30 second-ish wait)
OS - Windows 8.1 Browsers: Chrome 32.0.1700.107m and IE 11.0.9600.16476
Luckily, I recently attached my Facebook login as well to my SE credentials, which enabled me to login and ask this question.
After 20 minutes or so from my initial question - attempting to login with IE renders the following response from Yahoo!
It appears that either Yahoo! or SE is changing some configurations (maybe?) and the two are not talking well with each other anymore.