Why does new GUIStyle() give "object reference not set to an instance of an object" error?

I have a GUISkin (buttonGUISkin) initialized in the inspector with a Custom Style named butGUIStyle. I want to create several unique GUIStyle instances using new GUIStyle()
repeatedly with the GUIStyle from my GUISkin. I’ve used this basic structure successfully before. (See one of my other questions for more details) Before I had issues with naming Custom Styles. It seems the last time I updated Unity that problem went away and the Custom style name field can be used. But, now I get ‘not set to an instance of an object’ when using the same technique I, in fact, am using successfully elsewhere. Here is a code segment that fails, even when using “” as described in my previous question:

using UnityEngine;
using System.Collections;

public class guiskintest : MonoBehaviour {
	
	private GUIStyle[] btnGUIArray;
	
	public GUISkin buttonGUISkin;
	
	private	bool firstpass = true;
	
	public int pttcnt=4;
	
	void OnGUI () {
		
		if (firstpass) {

			for (int i=0; i<pttcnt; i++) {
			   btnGUIArray *= new GUIStyle(buttonGUISkin.GetStyle("butGUIStyle"));*
  •  	}	*
    
  •  	firstpass = false;*
    
  •  }*
    
  • }*

}
Any thoughts on what is going on would be appreiciated!

btnGUIArray is null!

inside the if(firstpass), you need to add btnGUIArray = new GUIStyle[pttcnt]