Apple TV vs. YouTube

Earlier today, I tried to view videos from my YouTube channel using my Apple TV. This had worked flawlessly before. I went to watch my videos, and discovered that I wasn't logged in to YouTube, so I tried to login to YouTube. I thought I was using the correct credentials, but I kept getting the dreaded "This account cannot be used with Apple TV" error message. I double checked my login/pass, and I was using the correct ones.

No dice.

I made sure I was using a Google+ Channel for my content (I am)

Checked for available software updates (there were, and I installed them)

Double checked my login/pass, tried some other login/pass combinations

Enabled 2-factor authentication on YouTube, and authenticated

Searched both here and elsewhere on the web for answers. Folks were recommending setting up an Application Specific Password. Tried that twice.

Tried disabling 2-factor authentication

Tried revoking both of the ASPs

Tried to login again using login/pass instead of ASPs.

No dice.

What am I missing?

Apple TV 2nd Gen

Software v6.2.1

Airport Extreme v7.6.4

Comcast/Xfinity broadband

Thanks in advance for any help you can provide.