You will want to post in this thread so the Tablo Ripper developer is notified. Tablo Ripper is no longer actively being developed but that’s your best shot.
Having said that, I have Tablo Ripper installed and have used it in the past and I’m NOT seeing the issue you are seeing as I can run it and it opens normally. Are you sure the pop-up you encountered was for Tablo Ripper?
And as a workaround while you are troubleshooting the issue, I also use TabloTools and it has the ability to export shows as well so you give it a try in the meantime.