JOHN WASSON commented,
Hi Mike. Correct, I know that sometimes searching for a solution on the internet can yield these old posts which end up being able to help folks even now--I know they've helped me! :-)
JOHN WASSON commented,
Peter K, I "suddenly" had the same problem. It turns out I had accidentally ticked the box for "Show... Hidden Notes and Rests" in View Menu. Could this be what happened to you?