Please make sure that you're running the latest version of the game by visiting your app store and verifying there are no available updates. Playing the latest version of our games ensures you'll run into as few bugs as possible. If there are no updates available, please try these troubleshooting steps:
1. Turn your game and any other apps off so that they are no longer running in the background of your device.  
2. If you have an account connected to your game, like Facebook, disconnect it.
3. Turn your device off and wait 10 seconds before you turn it back on. 
4. Log back into your game, verifying you're using the correct account. 
5. If these steps didn't work, please try a second time before contacting Support.