After installing the last MacOS Sierra update, I lost my camera on Facetime and Skype, and in web apps.I actually had this problem many times in the past, and often a reboot fixed it. However, I rebooted several times, and it did not solve the situation.I also tried several solutions on foruns, including killing the camera daemon without much success.What to do?
Camera not working on MacOS Sierra 10.12.6 (beta)
osx;camera
I ended up finding a fix for a similar problem for people that have Parallels installed. This fix works without having Parallels installed.This is a widespread issue on macOS Sierra   By running this fix you are resetting the Facetime camera. You should apply this fix each time you want to use the Facetime camera While I have VMWare Fusion, and not Parallels the fix worked for me. While Parallels KB insists on saying it is an interaction between their product and Sierra, I believe genuinely this is a MacOS bug.So for solving this, I downloaded http://kb.parallels.com/Attachments/kcs-40680/replug_facetime.zipand running it with the command:sudo ~/Downloads/replug_facetimemade the Camera work again.From the binary itself:replugging the Facetime camera device...Failed to create PluginInterface:The fix has to be applied again after each reboot.