Why can't apps (even the camera one) connect to my rear camera?

I've had my Fairphone 2 for less than a month and the rear facing camera will no longer connect to any apps. I can't use it at all. When I try to use it I get a message saying that the app cannot connect to the camera and the screen shows coloured stripes where the picture should be.

The camera worked great when I first got the phone. The front facing camera is fine.