This error message will display if you typed your email address or password incorrectly.
The service uses your email address as your login, so when logging in, be sure you are using the correct email address. It will be the same one used to sign up for the service, which may differ from the email address used to create your Xbox Live or PSN account.
If you have forgotten your password, you can reset it.
If you are certain you are entering the correct information but are still unable to log in, please try a different browser or try clearing your current browser's cache and cookies. Also, be sure to turn off any pop-up, ad, or script blockers, as they may interfere with the login process.