Do not use Application.LoadLevel, it is now depreciated. So I would assume it’s done that way for good reason.
Use SceneManager now.
using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement; // <<<<<< ADD THIS.
public class Example : MonoBehaviour {
// Use this for initialization
void Start () {
SceneManager.LoadScene ("NameOfScene"); // <<<< Then Do this.
SceneManager.LoadScene (0); // OR THIS (int = scene id in build menu)
}
EDIT:
And to change a scene by clicking Object, such as UI Button.
public void WhatEver(){
Same code as above with loading scenes, then drag and drop this script onto the button and feed it into the button OnClick at the bottom.
}