Are the Arcmesh materials broken? If so, how do I fix this? The materials for the Window Arcimesh (Using the Archimesh add-on) were all black.
I entered the Node Editor to check it out, and found this material organization.

I'm unfamiliar with what is trying to be accomplished here, as these nodes imported with the add-on. 
What are they trying to accomplish here? Is the node format outdated? What was trying to be accomplished?

And...
How would I go about restoring the previous settings? If I can't, how would I go about redefining these textures to look at least similar to what was intended?

(Apologies if these are too many questions; I'm looking to learn).
It's a bug. I recreated the material nodes in my own fashion in order to continue. However, the Archimesh add-on will need to be updated to truly resolve the glitch.