Please note that such issues usually happen because of a bad internet connection. To avoid such situations we can recommend you the following:
1. Ensure that your device is connected to the internet and that the connection is stable.
2. In case you are using a mobile internet connection, try switching to the WiFi.
3. Try to restart your device and run the game again.
In case the situation remains the same, please try checking the connection in other applications (games and internet browsers). In case there are also internet connection problems, most likely the source of the issue is the internet connection or your device.
Otherwise please contact our technical support and describe the issue in as much detail as possible: when did you first face the issue and what were you doing when the issue occurred.