[update 21.03.17] I started to get black viewfinder on my jolla C... I don't really know when it started, now I'm on snowboard vacation and when wanted to take some pictures, I noticed about black viewfinder on main camera. On front camera it sometimes work and sometimes also black. I didn't install any new things, but I did 2 new things: 1. I changed battery, that work perfect. 2. I now in French alpes with with roaming from my Israeli sim card. The connection dropped many times 2-3-4G, sometimes lost connection and reconnect again. Sometimes I feel a hot spot around the camera lens. That all.. Already tried: 1. killall -KILL mm-qcamera-daemon = not help 2. Reinstalling camera app = not help 3. Removing camera app + reboot + reinstalling camera app = not help 4. Disabling all patches = not help 5. Lipstick restart = not help 6. Reboot/shutdown - sometimes it started to work, but after some minutes I get the black viewfinder again. Today even reboot/shutdown get the same result (black viewfinder) = not help 7. Tried to play with dconf commands related to jolla-camera, but didn't find something that I can change for fixing this problem. 8. CSD tools camera tests - sometimes pass for both cameras, sometimes only for front camera.. Any other ideas for fix ? Thanks.