
Additional problem: I'm still on an old and tired Mac Pro that needs replacing and none of my usual apps can open the files. No Adobe apps and that includes the DNG converter, and not DPP either as the latest update can't be installed. So I used XnViewMP, an app that I recently purchased. It's a great raw viewer with lots of extras but I'm new to it so I'm out of my comfort zone. But it will have to do for now until I move to a new Mac later this year.
DPP update loaded fine on my (Win 10 upgrade) Dell xps I-7 3820 desktop from 2012, I think. Of course, your mac maybe really old!