Redefinition issue

Some of the nodes share the same internal name, for some reason.

Which version are you using, and which version did you start creating the shader in?

To fix it, go to settings and enable variable name & precision display, and then make sure they are all unique.

I remember doing the same thing in 0.36 and it worked well. This shader was created with 1.02
I didn't know about that option. It worked using it, thanks.