If you get this message on Zest recorder, it's because something is wrong with your browser permissions, or your browser is already sharing screen or video in another tab.
Just reload the page. Open Zest recorder and you should be able to authorise the microphone and the screen sharing again.
If reloading the page did not work, your browser might be already using screen sharing or video authorization in another tab: try to find this tab, or you can simply quit and restart the browser to make sure you don’t have any other tab sharing video.
If solution 1 didn't work