I have tried all the layer options per guidance, but Clone Stamp still refuses to work. I suspect its because I am continually being asked to select subject not matter what I select. Clone Stamp used to work all the time now I cannot use it at all. Please advise.
You are probably referring to the Contextual Task Bar. It's supposed to give you quick access to what you might want to do next.I find it intrusive, and seldom any help.
You can hide it in the Window menu, down at the bottom.
If @Semaphoric's suggestions don’t resolve the issue, could you please share a screenshot of your workspace with the file you’re having trouble with? That’ll help us get a clearer idea of what’s going on.