Pause Menu Issue (Black Screen)

Hi guys, I've been having an ongoing issue with trying to get any pause screen/menu to work in my game. I have tried out various tutorials with different UI methods and scripts but to no avail. The main issue I have with the script I'm using at the moment is that when I $$anonymous$$t play the screen is black, but I can hear all of the audio and AI working, I just can't seen anyt$$anonymous$$ng. When I disable the script, it works as normal. I've tried disabling the Canvas object and switc$$anonymous$$ng from GUI text to UI text as well as trying to use textures instead. but still no solution. I know it's probably somet$$anonymous$$ng really obvious, but i'm rather confused. Here is the script I am using either way...

 #pragma strict
 
 
 private var pauseGame : boolean = false;
 private var showGUI : boolean = false;
 
 function Update()
 {
 
 if(Input.GetKeyDown("p"))
 {
 
 pauseGame = !pauseGame;
 
 if(pauseGame == true)
 {
 Time.timeScale = 0;
 pauseGame = false;
 
 showGUI = true;
 }
 }
 
 if(pauseGame == false)
 {
 Time.timeScale = 0;
 pauseGame = true;
 
 showGUI = false;
 }
 
 if(showGUI == true)
 {
 gameObject.Find("Pause").GetComponent(Canvas).enabled = true;
 }
 
 else
 {
 gameObject.Find("Pause").GetComponent(Canvas).enabled = false;
 }
 }