Setting _Metallic property on Material failing

Hello

Trying to set metallic property on material but is constantly failing.
When using Standard Roughness, should this be set with _Metallic property?

Running 2017.2.0f3

Error:

Simple editor script to replicate:

Code (CSharp):

1. using UnityEngine;
2. using UnityEditor;
3. public class TestMetallic : MonoBehaviour
4. {
5.     [MenuItem("Assets/Test Metallic...")]
6.     public static void test()
7.     {
8.         Material material = new Material(Shader.Find("Standard (Roughness setup)"));
9.         Texture2D t = new Texture2D(256, 256);
10.         material.SetTexture("_Metallic", t);    
11.     }
12. }

 

https://docs.unity3d.com/Manual/MaterialsAccessingViaScript.html

I don't see "_Metallic" anywhere. But there is "_METALLICGLOSSMAP".

 

Many thanks!

material.SetTexture("_MetallicGlossMap", t);