Hi PinkElephant,
Yup, I had already checked that the extension is ticked. Unchecking the box removes the WebClipper toolbar button from Safari, selecting it brings the toolbar back, but still in it's 'greyed out' state.
I then shut down Safari, removed the WebClipper app to the trash. Reloaded Safari and checked to see that the WebClipper extension was removed from Safari/Preferences/Extensions, and it was gone.
I re-installed WebClipper, started Safari, and checked that the WebClipper extension was there, it was. I checked the tick box, and the WebClipper extension popped up in the toolbar, but it is still 'greyed out'. I shut down Safari and restarted it, but the WebClipper toolbar icon is still 'greyed out'.
I am not sure what to do next. Any ideas most appreciated.