Had multiple annotation boxes open at the same time. Got a scary message (image above). Couldn't click or scroll. Went to Chrome > About to find Chrome version number and it hard refreshed, solving the problem — and apparently also not losing my unsaved annotations.
Running Chrome 125.0.6422.142
Had multiple annotation boxes open at the same time. Got a scary message (image above). Couldn't click or scroll. Went to Chrome > About to find Chrome version number and it hard refreshed, solving the problem — and apparently also not losing my unsaved annotations.