First, determine which error message you are seeing:
"Email or screen name provided was not found."
In this case double check the spelling on your screen name, or try entering your email address instead (either should work). In the case of email, make sure you're using the same email address you used to make your account on Hydrow.
Note: If you crowdfunded Hydrow through Indiegogo or pre-ordered on our website, you will still need to create a new account the first time you log in to either Hydrow or the iOS app. No account is created for you automatically. If you were previously a beta tester, however, you should be able to log in and use the same account to keep your progress.
"Password provided is not correct"
Check that your password is being entered correctly using the "Show" button. You can also try the process in this article to reset your password.
If you are receiving a different error message than either of the above, or a different symptom entirely, please Contact Hydrow Customer Care. Make sure to describe the problem and attach a screenshot from your iOS device to help us better understand the nature of your issue.