Do you have any special characters in your current username and/or password, such as an % or + or $ etc?
It would appear that when NOW TV issued their last 'app' update for (Roku) hardware playback devices, it broke support for some special characters...
Usually your NOW TV account 'User Name' is not your email address 😉
Can you please let me know why it is not working on the Roku?
Provided your NOW TV 'User Name' and 'Password' are correct, there shouldn't be a problem logging into the NOW TV service!
Any more than that, I'm not aware of as I don't work for NOW TV!
Am experiencing the same problem as original poster. Tried two accounts on NowTV - both are successful on website but both fail on Roku's NowTV app. All other apps working so not Roku or network issue.
Anyone else with this problem?
Logged in on website and added payment details - that was it. Now am able to login, first try, on Roku.
That was it.
Very poor user experience and documentation. It should have given an appropriate message and job done. That would be far too obvious. That said, the reality is probably a badly designed system with an unintended side effect that was not widely known or understood.
Welcome to the forum. Is this the first Roku and/or NOW TV box you've set up? If so, the NOW TV app on these doesn't always work well with passwords with special characters in, make sure yours just contains letters and numbers, or change if not. Also, check on your My Account > Account Details page
to see what your username is, and try logging in with this rather than using your email address.