Greggory

I'm working with Delphi 10.4.1 and everything was going along quite well but then one day the four icons on the IDE's "View" toolbar just quit working. They give the graphical appearance of being clicked but they don't toggle the form/unit or whatever; nothing happens when I click any of them. All the buttons on the other toolbars work and I can work around this but it's inconvenient and distracting. Has anyone else run into this or have an idea what would cause such a thing?