I have searched the user manuals and can find no information on using F keys and how to cancel a command I have done. macOS 10.8.5
I foolishly followed some advice and used F5 button for something. Now there is a permanent open field on all windows and Excel won't let me input into individual fields.
I don't remember what I did, why I did it, and don't know how to undo it. Thick black line flashes round a field box, or any button.
How can I undo this action?