Try out the following steps to fix this issue:
- Ensure you are connected to fast and stable Wi-Fi
- Ensure you have entered your correct Facebook details
- If you have the Facebook app installed on your device, trying logging out and back in again. Then try to connect to Facebook again from the game
- If you don't have the Facebook app, install it and see if that helps
Should you still have issues after that, make sure to contact us.