Try the following steps to see if the problem can be solved.

• Please make sure that your device meets the system requirements.  
  If your device does not meet the system requirements, the application may not start.
• Restart the application.
  Please close the running application and try restarting the game.
• Restart the smartphone.
  Turn off the device and then turn it back on.
• Switch to a stable connection or switch from Wi-Fi to a carrier connection.
  If you are using a carrier line, please make sure that the connection speed is not limited.
• Set [Graphics] to lightweight *When the game starts up
  You can change it from Home screen > Menu (three-line icon in the upper right corner) > [Graphics].
• If you are using an Android device with a microSD inserted, check the location where the application is installed.

*If you confirm that the application is installed in the microSD, move it to the main unit storage.