Verify that you are tapping on the 'Log in' button when attempting to log in. If you tap on the 'Sign up for Metal Pay' button, you will begin to create a second account, which isn't allowed per our User Agreement.
Verify that you are entering the correct password. If you forgot your password, please follow our "How do I reset my password in Metal Pay" guide.
If your issue persists, or if you receive an error message, please open a support ticket by shaking your device while inside the app and input the email address you used when signing up for Metal Pay. Alternatively, you can open a support ticket through our helpdesk.