Hey guys!
I'm contacting you concerning a problem i have with the material layering plugin. I recently updated my Substance Painter to the version 2.5 to be able to use all the new functionalities.
I'm also using it to texture using the multi material layering technique.
When i try to open the .json file in Unity 5, i get that error:

I thought it came from my exports from Substance Painter. So, i cleaned my shelf from all previously imported materials. Re imported them cleanly and re did my texturing.
When i export the textures using Document Channels + Normal + AO (With Alpha) and tick the "Shader Parameters" option i still get the same issue in Unity 5.
The custom materials used were created using Substance Designer 5.5 so that may be the issue. I'll keep doing tests and ressearch on my end, but it seems to me there is still a problem with the Unity plugin itself.
Could really use some help on that one.
Thanks!
Cheers!