InDesign: "Backgroud Tasks" constantly spinning for "add font"

Doing a rather large book layout after being away fron InDesign for a while, and suddenly BACKGROUND TASKS is constantly spinning up in my menu panel.

When I click on the "spinner," it says "Adding Font - Roboto..." This seems to be perpetual, because it never stops spinning.

I think I remember a nifty shortcut to locate and change a font, but I'm not having luck - as I mentioned, I've been away for a while..

I apologize for the somewhat simple question (I used to handle this pretty simply) - - Is there a quick and efficient way to find this wayward font and eliminate it so TASKS can rest?