21-01-2018 14:51
21-01-2018 15:35
@Anonymous User
Welcome to the forum. If you open the NOW TV app on your first box and go to the My Account screen on the menu it will show you what username you are logged in as. Make sure this is the username you are using to log into the second box.
If you've recently changed your password on your account make sure it only contains letters and numbers. If it doesn't change your password so that it does and try again.
Couple of other things you could try if that doesn't help so post back if you're still stuck.