The script that i use for all the buttons in the menu

pragma strict

 var pauseKey : KeyCode;
 
 var PauseActive : GameObject;
 
 function Update () {
     if (Input.GetKeyUp(pauseKey) && PauseActive.GetComponent(Canvas).enabled == false){
         Pause();
     }else if (Input.GetKeyUp(pauseKey) && PauseActive.GetComponent(Canvas).enabled == true){
         UnPause();
     }
 }
 
 function Pause () {
     PauseActive.GetComponent(Canvas).enabled = true;
     Debug.Log("Paused");
     Time.timeScale = 0f;
 }
 
 function UnPause () {
     PauseActive.GetComponent(Canvas).enabled = false;
     Debug.Log("Un-paused");
     Time.timeScale = 1f;
 }
 
 function SaveGame () {
     PlayerPrefs.SetInt("LevelNumber", Application.loadedLevel);
     Debug.Log("Game has been saved!");
 }
 

on the first level if i press the pauseKey the ui shows up and all the buttons are selectable, if i do it on the second level or any other level it shows the ui but the buttons arent selectable i have it setup in the exact same way on ever scene. if anyone has any ideas how to fix this please let me know as its been frustrating me for 3 days now!