Null reference exceptions on first access

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class UIManager_Language : MonoBehaviour {

	public GameObject LanguageMenu;
	public GameObject EnglishButton;
	public GameObject GermanButton;
	public GameObject ItalianButton;


	// Use this for initialization
	void Start () {
		SetLanguageButton();
	}
	
	// Update is called once per frame
	void Update () {
//		SetLanguageButton();
	}

	public void ShowLanguageMenu()
	{
		LanguageMenu.SetActive(true);
	}

	public void HideLanguageMenu()
	{
		SetLanguageButton();
		LanguageMenu.SetActive(false);
	}

	void SetLanguageButton()
	{
		Debug.Log("LANG: " + I2.Loc.LocalizationManager.CurrentLanguage);
		if (I2.Loc.LocalizationManager.CurrentLanguage.Equals("English"))
		{
			EnglishButton.SetActive(true);
			GermanButton.SetActive(false);
			ItalianButton.SetActive(false);
		}
		else if (I2.Loc.LocalizationManager.CurrentLanguage.Equals("German"))
		{
			EnglishButton.SetActive(false);
			GermanButton.SetActive(true);
			ItalianButton.SetActive(false);
		}
		else if (I2.Loc.LocalizationManager.CurrentLanguage.Equals("Italian"))
		{
			EnglishButton.SetActive(false);
			GermanButton.SetActive(false);
			ItalianButton.SetActive(true);
		}
	}
}