Had that link worked, it would be terrific.
Alas it doesn't work for me.
My scenario is that I bought one, then another one.
They both work.
Then I bought another and it had this problem.
I even bought a "Genuine" Uno.
It too doesn't work. SAME PROBLEM.
Tried other board types - as suggested in other posts from people with similar problems.
Weirdly enough I can still talk to my first Arduino.
So I am really at a loss to what is going on.