Engrave toolbox options not selectable

In one of my projects, the Engrave toolbox options are not selectable except for Frames (see attached screen shot clip). All the options are available in another project, so I presume I must have triggered some setting that disabled the options. Any clues how to enable this again?

Welcome to the forum, hexahedron. This is a small bug in Dorico 3.5 that occurs when you close the master page editor by e.g. switching mode rather than clicking the ‘Close’ button in the little bar below the toolbar. You should find that reopening the project will take care of the problem. Sorry for the inconvenience! This will be fixed in the next update.