The badge that can appear on selected apps in the macOS Dock is a helpful reminder that you’ve got something that requires attention. But when the badge “sticks” and continues to remain in place even after you’ve carried out your task? It’s a persistent itch you want to scratch.
This can happen in the Messages app, as I discovered recently after texting myself a link when I couldn’t get the oh-so-reliable AirDrop to work between my phone and computer. The link arrived, but the badge wouldn’t disappear. Closing the conversation in the list in the left of the Messages window didn’t help. Nor did quitting the app.
I tried a suggestion many forum posters around the Apple universe of discussion boards recommended for stuck Dock icons. In the Terminal app, enter exactly the following and press return: