The first thing is to restart in Safe Mode. Google will tell you how to do that.
Once you're in that way, you need to go to the settings and switch back to the default profile. It'll probably be called "Mac.icc" or something similar.
Great. So can you show me another screenshot, of you attempting to clone on a duplicate of the Background layer of an image. Make sure there are no other layers in the image, only the Background and the duplicate.
If you could follow the 100% crop instructions, that would be much appreciated, thanks. Sorry to be a pain. It helps me to be sure of what I'm looking at.
And is it also doing it if you try cloning on a duplicate of the Background layer, rather than a blank layer?
I'm just trying to narrow things down, you know.
This is a funny thing that happens to a lot of people. We don't really know why, to be honest. It doesn't seem to matter, though.
How's your print match?