How to Solve the Problem of 'iPhone 6S Camera Not Working'?

For hardware problems - In most cases a hardware problem requires professional attention and it is always advisable to take the phone to the nearest Apple Store especially if the phone is new and the problem could be the manufacturers fault. You could also get in touch with the Apple Support Center to get further guidance. This, however, rarely happens.

For software problems - Luckily most software related problems are easy to deal with and you do not have to necessarily get a professional to rectify the problem for you.

1. If the camera stops working because the phone software is not updated, then boot up the phone. Press the home and power button until the Apple logo appears on the screen. When the logo appears, stop pressing both tabs and wait for the phone to boot up. Where the camera has been functioning but stops working even after updating the software, you should check whether the camera lens is dirty or there is something blocking the camera, for example the iPhone case. Use a microfiber cloth to wipe dirt off the lens. If the dirt is inside the lens, take it to an Apple store and get the lens professionally cleaned.
2. If the camera stops working as a result of a change in settings, then resetting default settings will solve the problem. To reset default setting you need to choose "General Settings", go to "Reset" and press "Reset All Settings". You do not need to worry about losing data after resetting the default settings. Another trick that has been proven to work is to set the phone as new. This is done by connecting the phone to iTunes and choosing the set up as new phone option.
3. If your iPhone camera works perfectly after you have followed any of the above steps, then you have nothing to worry about and you can continue using it as long as there are no more problems with the camera or with the general functioning of the phone. If, however, the phone camera does not work after following any of the above processes then visiting an Apple Store or getting in touch with the Apple Support Center should be your next course of action. From there professionals can identify the reason why your iPhone 6s camera stopped working and offer the best solutions available.