1. Make sure that you type in the correct ID or password. If you forgot the password, there are two recovery options:
From unifi TV box : Only works if you are login with unifi TV ID. Go to Setting page to reset.
From App : If you are login with your mobile number, you can reset the password on Forgot Password button on the login page.
2. Possible Connectivity Error
Check your data or Wi-Fi connection.
3. Maximum Device Login Reached
Try to logout from other device that is currently running the app.
4. Failed to login using Facebook ID
Clear the app cache and re-login or re-install the app