When I encounter an odd error message and its solution, I make a note. This is one of those notes. I want solutions to turn up better in searches for other Avid users (and myself). As with all error posts on the site, the casual reader can just skip ahead to other less-technical content.
After trying many solutions, the problem boiled down to Avid FilmScribe not being able to work with stereo tracks. Duplicate your sequence, ctrl-click (right click) on the track and split it to mono. Do the same for your comparison sequence. Now it “works”.
Work for Avid? Know more about what’s going on? Know a better solution? Leave a comment below.