Null Reference Exception After refering to an Array

Hey guys im making a zombie survival game and I am facing a problem with levels. I have basicly made a menu where you can edit your player and in this menu I want my player's level to be appeared.. the problem is that i have set up the level up logic in a different script so, i am refering to it from my main menu script (as my player edit screen is in my main menu) my code is this:

 public Texture[] levelTextures;
 public string playerName;
 
 public void OnGUI()
 {
 GameObject manager = gameObject;
 PlayerController pCont = manager.GetComponent<PlayerController>();
 
 GUI.Label(new Rect(Screen.width / 2 + 115, Screen.height / 2-25, 100,100), "Player Level", mainMenuLetters);
 
             GUI.Label(new Rect(Screen.width / 2 + 50, Screen.height / 2 + 35, 100,100), "[" + playerClan + "]" + playerName + ": " + pCont.playerLevel, mainMenuLetters);
             GUI.DrawTexture(new Rect(Screen.width / 2 + 100, Screen.height / 2 + 35, 100,100), levelTextures[pCont.playerLevel - 1]);
 }

Note***: playerLevel is an int variable.

My Error is this: NullReferenceException: Object reference not set to an instance of an object MultiplayerScript.MainMenu () (at Assets/Scripts/MultiplayerScript.cs:475)

Note2***: line 475 = GUI.Label(new Rect(Screen.width / 2 + 50, Screen.height / 2 + 35, 100,100), "[" + playerClan + "]" + playerName + ": " + pCont.playerLevel, mainMenuLetters);

I really can't solve this problem on my own i have tried everything please help me.