My Camera won't start.

[AC Question]

My camera app will open but the screen is just black and it will not take any pictures. I've had the phone for less than a month with no drops or spills. I've tried clearing the cache, deleting data, force stopping. Nothing has worked. I've even gone to the extent of doing a backup and factory reset, with no success. Please help.

 

[belodion]

Have you tried Safe Mode, to test whether a third-party app is causing trouble?
However, it does sound much more like failure of the camera module, or some other internal component.

 

[Reality561]

This solved it for me. The Fast Boot setting caches stuff in memory and loads it for faster start. My camera wouldn't start after trying everything, from disabling apps to rebooting, etc. So I wondered if something about it that had been cached for the Fast Boot was corrupt. So I turned off the Fast Boot in Settings and restarted the HTC DNA phone.

It worked. Camera is back and working normally.