Mac cannot find camera anymore

My Mac cannot find the camera anymore - to solve the problem I already tried all the 'classic' methods (like check if you have permissions or if there are limitations in the use of the camera in your Mac) - oc didn't work. So I downloaded EtreCheck and got rid of the orphan files (this is the only thing I am able to do as I am not an expert honestly). Still no luck, so decided to run it again and seems as if there are even more orphan files (and I don't even know if this is the real problem)? I followed the instructions to the tee....What did I do wrong?