This is an error specific to 2017.2 I believe. It was working in 2017.1.1 last time I tried.

Thanks for the reply! Looking forward to the fixes. What have you been busy with? Budget Cuts update? :D

It seems to have been around for a while. I made a post here http://shaderforge.userecho.com/topics/1466-unity-201701f3-previews-all-white/#comment-5071 about it. See if that make shift helps you.

Using Real-time node Rendering under settings kind of helped a bit but still have to disable skybox for it to "work". The drawn previews in this look reversed while some previews have white outline artifacts showing up.