Can you please try downloading the release candidate?
http://discourse.mcneel.com/t/rhino-for-mac-second-release-candidate-for-5-1/25289
This was the version the latest upload was built against. Dan or Steve (or someone) might have to comment about how loading of plugins will work (ie nominating version) with WIP and released versions.
If you can’t install the release candidate, let me know and I’ll build for the WIP that you have.
Thanks,
Jon