Hi,
I am creating a VR menu using VRTK and the VRTK_UICanvas.cs script is not inside any of the Tillia packages so I installed the 3.3 package. Now I have all the script I need but unity prompts this error every time:

I am certain that there is a MonoBehaviour class as the code is as follows:
// UI Canvas|UI|80010
namespace VRTK
{
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using System.Collections;
using System.Reflection;
using System;
...
[AddComponentMenu("VRTK/Scripts/UI/VRTK_UICanvas")]
public class VRTK_UICanvas : UnityEngine.MonoBehaviour
{
...
I also tried to make some adjustments but to no avail:
// UI Canvas|UI|80010
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using System.Collections;
using System.Reflection;
using System;
using VRTK;
...
[AddComponentMenu("VRTK/Scripts/UI/VRTK_UICanvas")]
public class VRTK_UICanvas : UnityEngine.MonoBehaviour
{
...