1. Please make sure you have updated the game to the latest version;

2. Make sure your device meets the minimum system requirements for gaming. Currently, the minimum device and operating system requirements are as following, they may be changed in the future as we keep optimizing the game:

- Apple devices with iOS 10.0 and later, not including iPhone 5s and earlier iPhones, iPod touch 5 and earlier iPods, iPad 1 and 2, iPad mini 1, iPad Air, with at least 1GB RAM.
- Android devices with Android 4.4 and later, with at least 1.5GB RAM.
- At least 1GB free space.
- Stable internet connection.