I am getting the same error on lots of clips. Premiere 14.9.0. Just right-clicking clip in timline and hitting "reveal in project". Spinning ball and the dialogue box. I can match frame and "reveal in finder" just fine. Anybody have any ideas?
This is one of the issues with Productions. If you open a project outside of the Production you can't easily access the media; it may be inside another project in that second Production so it's sort of invisible. I would do this:
Open the other Production file
Open the project. Then do your "reveal in..." command.
Once you find the media, copy it into the bins of a new blank project.
Open your original Production and then add the new project with the media into it.