Ok. So if I remove that repository, that will probably fix the error message. I think you answered it.
Yes this is 15.2. I was forced to select a tag, but it didn’t offer 15.2. I choose 5.2 since it was the closest, but should have emphasized that in my post. Sorry for any confusion, but it looks like you figured it out.
I do need to upgrade, maybe that is the final take home message.