This can happen if you have more than one Facebook account signed in on your cell phone. This includes your phone's browser.
To fix this, please follow the steps below:
- Log out from all Facebook accounts that are currently signed in on your phone. Make sure that you check your phone's browser twice to make sure that it's not signed in automatically.
- Check to see whether the game has been fully updated through your app store.
- Clear the game's cache through your phone's settings, restart your device, and log in to the game via your Facebook account.