ERROR: 0:2440: 'node_vect_math_dot_product'

Browser CONSOLE ERROR message(S):
” v3d.WebGLProgram: shader error: 1282 35715 false gl.getProgramInfoLog Must have an compiled fragment shader attached. ERROR: 0:2440: ‘node_vect_math_dot_product’ : no matching overloaded function found ”

” v3d.WebGLShader: Shader couldn’t compile. ”

” v3d.WebGLProgram: shader error: 1282 35715 false gl.getProgramInfoLog Must have an compiled fragment shader attached. ERROR: 0:2507: ‘node_tex_musgrave’ : no matching overloaded function found ”

Browser/operating system: e.g. Chrome 73 / Window 10, Safari / iOS 12
Firefox 70.0.1 (64-bit) Windows 8.1
Version 2.17.0pre1
Blender 2.81

What steps will reproduce the problem?
using Dot Product in Math Node(?)

What is the expected result?
the copper metal texture should show as usual

What happens instead?
object with material does not show, error message in console appears

NOTE: i’ve never voluntarily used “Dot Product” as a math node on my own.
It IS, however, a node in a group node setup i use in a few materials which i downloaded from BIS (Blender Interplanetary Storage) https://b3d.interplanety.org/en/bis-online-blender-material-storage/
I use these materials often, with no problem.
not sure why it may be causing a problem.
(maybe this is not the source of the problem?)

EDIT: tried it in blender 2.80 and verge 2.16
same problems.