script error in web GL

I would like to understand this error, the strange thing is that it is having trouble with a script that runs fine in another version of the same environment.
Any help on understanding what I am looking at here would be helpful, Thanks!

The script(s) in question are -

using UnityEngine;
using UnityEngine.EventSystems;
using System;
using UnityEngine.Events;

public class PressHandler : MonoBehaviour, IPointerDownHandler {
	public class ButtonPressEvent : UnityEvent { }
	public ButtonPressEvent OnPress = new ButtonPressEvent();
	public void OnPointerDown(PointerEventData eventData)  {
		OnPress.Invoke ();


using UnityEngine;
using System.Runtime.InteropServices;

public class OpenLinkJSPlugin : MonoBehaviour {
	public string DocToOpen;

public void OpenLinkJSPlug() {
	private static extern void openWindow (string url);

I did find the answer, so I thought I would post if anyone following or finding this is interested.
I was missing a file in my plugins folder setting the path to use the OpenWindow.jslib in my WebGL build.