"Clip to DEVONthink" does not do anything

I have used DEVONthink personal for many years. “Clip to DEVONthink” has never done anything for me. I just re-installed it and tried it again. It still does not do anything. When I click on the icon in Safari’s toolbar, the icon becomes gray. When I release the click, it returns to its normal appearance. Nothing else happens. I wondered if something is being put in my database, but that is not the case. I wondered if something was being copied to the clipboard, but that is not the case. I wondered if the extension is specific to DEVONthink Pro, but the help information says that it is not.

How can I get “Clip to DEVONthink” to work?

All my software is current.

Thanks.

Which version of macOS & DEVONthink do you use? The extension should open a window, see DEVONthink’s menu File > Clip to DEVONthink…

macOS 10.12.2
DEVONthink Personal 2.9.8

Suddenly, it’s working today. No idea why.