The projector plugin’s “no data” screen has three vertical scrollbars in Firefox: ![Screenshot of the projector plugin’s “No checkpoint was found” screen in Chrome and Firefox, with three consecutive vertical scrollbars in Firefox][ss] The main view (i.e., with data) has two vertical scrollbars. There shouldn’t be any in either case. [ss]: https://user-images.githubusercontent.com/4317806/98718440-4f96dc80-2343-11eb-88b9-895f78282ee1.png