If your device regulary freezes, doesn't respond or crashes and displays errors, we recommand you to follow this guide (make sure to do it step by step in the order set below):  

• Restart your device by pressing and holding the power button. If any menu is displayed, do a reset 
• Search for any updates for your device and your applications
• Check the memory remaining  in your device, if your device memory is full, your device will work slowly. 
• Reset your device to return it to its original (factory) settings. This operation should be a last resort before contacting our customer support team as it will completly erase the content of your device.