NFL Network (via TVE; Armstrong provider) stopped working a few weeks ago and I was getting the "nfl media: 401 Unauthorized error on my Apple TV. I saw some similar posts and that users were able to resolve by rescanning the channel/channels on the TVE source.
When I rescanned the channel, I received the following Error: "nfl media: 401 Unauthorized: Grant id=[385088052], permissions=[] insufficient for MediaObject mcpId=[US-508-IN-264406], authorization=[MVPD], permissions=[NFLN]"
I am able to stream from a computer from nfl.com. I haven't tried removing the source and re-adding as I am concerned that I will lose "Favorited" channels and have issues with recording passes.