In most cases, the Wi-Fi connection is lost. Check your device settings under the Settings app > Wi-Fi. Sign in to your Wi-Fi network again, then go back to Singa.
Note that sometimes your device may require resetting your network connections if the connection is poor. Settings > General > Reset > Transfer or Reset iPad > Reset > Reset Network Settings. After that, follow the steps above to log in again.
Did this help? If not, contact us on firstname.lastname@example.org and we will look into it for you.