Do you have a TV package with Mediacom that includes A&E? A re-authentication error usually appears because you've signed in with a Mediacom account, but your service only includes internet (or your TV package doesn't include A&E).
You'll need the channel included in your TV package to watch locked programming.
If you don't have a TV package, please disconnect your Mediacom account to see unlocked programming.
For more information, see: I don't have a TV package. Can I subscribe directly to A&E?