Meowch! Sorry to hear that, but don't worry. We know what to do.
Please check your Internet connection. It should be perfect for the app to run correctly.
Resetting your Wi-Fi router can fix the issue.
2. Turn your device off;
3. Turn your device on by holding the power button;
4. Start the game to see if it works again.
Usually, it helps, but please don't hesitate to contact us via the Support button (you can find it in the game settings) if the issue persists.