Please follow below steps for troubleshooting：
1. Turn on the camera and try to take picture by volume key to see whether it works.
Note: Please turn on Camera -> Click the function menu at left top corner -> Set [ Volume key as Shutter ]
2. Restar your device.
3. Access to Safe mode ( long press " Power key "> tap and hold " Power Off " > Tap " OK ")：If your device works well in safe mode, malfunction might be caused by 3rd party apps. Please reboot your device and check again if it works well.
4. Backup your data and perform factory data reset.
