sudo killall VDCAssistant solution didn’t work at all, as well as, reseting my NVRAM.
After a lot of debugging and trial and error, I found out that the problem originated from the fact that I used Dropbox and had created a symbolic link in the place of the
The solution is to open
~/Library/Preferences/com.apple.PhotoBooth.plist with Xcode and change the link of
~/Pictures/Photo Booth Library to the absolute path of your new pictures folder.