Inherit Material (swapping)

Hi,
I'm having issues displaying textures using the Fast Preview tool.
Material colours display fine but the texture maps do not.

When I export these scene to a html file and open in Chrome, the textures are there.

I'm also getting the error message: warning section is disabled for node materials and static objects.

I have disabled node materials to try and fix the problem but there is no change. (image attached showing error).

Here's a blend file showing the material swapping working (html also). This has stack materials with diffuse colours only. There are no node materials.
If I try to add textures, though the stack or through the node editor… the whole thing breaks.

My main aim is to make a product configurator where materials can be inherited from small swatches. I'm so close but can't get it working