Tested it on Windows 10 Home and on a Mac OS SIerra 10.12.3 , both didn't work.

I tested Unity 5.5.0f3 and 5.5.2f1 with SF1.35. Still doesn't work.

Yes I downloaded the latest SF version from the store. That is so weird. The project was literally empty and the version was a 100% 5.5.0f3. I still have project. You can download it here https://www.dropbox.com/s/u1z08l0ragcfp8m/Shaderforge.zip?dl=0. Maybe that helps :) Thanks for your efforts!

Even with an empty project on 5.5.0f3 I'm still getting the same errors.

So since we are primarily working with 5.5.0f3 I tested your steps there first because it was unusable as well. So for me it didn't work. Still the same three errors.I will try and create outside of our project and see if it works.