Still the same problem, I reinstalled unity, did a project from scratch, installed Playmaker from asset store, then installed ecosystem 0.51, beta feature on or off, he download the files as empty object ...
http://imgur.com/a/4dSkLI don't know what to do anymore, this is super annoying.
I was using it prior to the version 2017.1.0f3 on this same computer without any problems. I am gonna try to install 2017.2 beta to see if it does something.
Edit : It works with 2017.2 beta but not 2017.1.0f3