I have a half dozen or so of ST-Links that I bought or that came with boards. A couple of them refused to work. Investigating, after all, they are very simple, I discovered that the pin labels on the cover DID NOT MATCH the pin labels on the enclosed pc board. Wiring to program using the pin labels on the pc board itself, the units programmed just fine. So if you have a ST-Link that doesn’t want to program, pull the cover off and look at the pin labels on the pc board and see if you have it connected properly.
Irv, you may want to give this warning next video you do that uses a ST-Link.