Nik Collection is no longer updated by Google. The last supported version was CC 2015.
I think most things work fine. Not sure exactly what doesn't work with CC 2017.
I've tried with PS 2017.1.0, Dfine didn't work, it started the process but never end.
Probably I will try PS 2017.1.1
I have no noticed no issues with Nik Collection on Adobe Photoshop Version: 2017.1.1 and Mac OS 10.12.4
Hello, I've upgraded PS to 2017.1.1 (macOS 10.12.5) Nik Collection works fine, just low definition of the image inside the plug-in.
To recap at my side with macOS 10.12.4 and PS 2017.1.0 all the nick plugs-in worked very slow and Dfine didn't work at all.
With macOS 10.12.5 and PS 2017.1.1 it's possible to continue to use nick collection.
Anyway I have to plan a change of my workflow in a near future.