1. Please make sure that you have the latest iOS version. Go to Settings > General > Software and check if an update is available. C.A.T.S.: Crash Arena Turbo Stars is not compatible with iOS versions lower than iOS 8.0.

2. Make sure you have enough free space on your device. Go to Settings > About and check "Capacity" and "Available". You can free up space by removing unnecessary apps. 

3. Close any apps that are running in the background. Double-tap the "Home" button to see all the apps which are currently running and swipe up to close them. Alternatively, you can try restarting the device (turn it off and on again).

4. If you are using a jailbroken device, we cannot guarantee a smooth game performance.

If nothing helps, please contact us with detailed information about your device and OS version and we will do our best to help you.