There could be several reasons why.
Most of the time is that you have entered the email address or password incorrectly. If you signed in with Facebook the first time, you will need to click the "Sign in with Facebook" button to log in.
There could be several reasons why.
Most of the time is that you have entered the email address or password incorrectly. If you signed in with Facebook the first time, you will need to click the "Sign in with Facebook" button to log in.