The error message "0066: No Account Returned from UPDA" may mean that you are signing in with a DIRECTV/AT&T UserID that is not connected to a TV package with DIRECTV/AT&T. First, please verify that you have a TV package with DIRECTV/AT&T that includes A&E in your TV channel lineup. (If you have internet or phone service only, you will not be able to unlock A&E content.)
If you are sure you have a TV package, please try disconnecting DIRECTV/AT&T from A&E and then logging in again. This step usually resolves the issue.
If your issue is not resolved by reconnecting, please check whether you have more than one UserID on file with DIRECTV/AT&T: https://m.att.com/my/#/forgotLoginLanding?Flow_Indicator=FID
Go through the steps to recover the UserIDs associated with your account. If you find that have more than one UserID on file, please make sure you are signing in to A&E with the UserID that is connected to your TV package (not your internet or phone package).
If you do have more than one UserID, you can combine them into one sign-in to use with A&E by following these instructions: https://www.att.com/support/article/directv/KM1321321. Once you have combined UserIDs with DIRECTV/AT&T, please try connecting to A&E again using your combined UserID and new password.