Please be assured and perform following methods to resolve the Camera issue:-
1. Please clear data or cache of Camera Application(Tap Settings > Apps > Camera > Storage > Clear Cache/data).
2. Reset the Device:- Kindly create data backup of your device via SMART switch mobile application or http://www.samsung.com/in/support/smartswitch pc suite How to reset:- Settings>General Management>Reset.
If the issue still persist, kindly register your concern in Samsung Members app (Samsung Members app > Get help > Feedback > Error report/ask question). Note: Please send device log files within 15 minutes of issue occurrence along with the exact issue details.
