Facebook log in support is currently not working.
This is being looked in to and we will try our best to retrieve the function as soon as possible.
Until then, please use the following method:
1) Go to the login page
2) Click forgot your password
3) Use your facebook login email to reset your password.
4) Player will get an email with username/reset password link
5) Use username and new password to log in the game.
Sorry for the inconvenience.