Application.LoadLevel crashes unity

I was playing with the roll a ball tutorial and was adding more things to it. I wanted to add multiple levels but when I run Application.LoadLevel it crashes. At first it told me to add the scenes to the build settings, so I did. After that it just crashes when I run the game. I tried switching to scenemanager but the import does not work.

 using UnityEngine;
 using System.Collections;
 using UnityEngine.UI;
 using UnityEngine.SceneManagement;
 
 public class PlayerController : MonoBehaviour
 {
 
     public float speed;
     private int count;
     private Rigidbody rb;
     public Text countText;
     public Text winText;
     public Text loseText;
     public Text hubText1;
     public Image backImage;
     public Button startButton;
 
     public GameObject pickup1;
     public GameObject pickup2;
     public GameObject pickup3;
     public GameObject pickup4;
     public GameObject pickup5;
     public GameObject pickup6;
     public GameObject pickup7;
     public GameObject pickup8;
     public GameObject pickup9;
     public GameObject pickup10;
     public GameObject pickup11;
     public GameObject pickup12;
     public GameObject pickup13;
     public GameObject pickup14;
     public GameObject pickup15;
     public GameObject pickup16;
 
     private bool win;
     private bool StartClicked;
 
     void Start()
     {
 
         Application.LoadLevel("Level1");
         //SceneManagement.SceneManager.LoadScene("Menu_Level"); gives error
         hubText1.gameObject.SetActive(true);
         startButton.gameObject.SetActive(true);
         backImage.gameObject.SetActive(true);
         loseText.gameObject.SetActive(false);
         winText.gameObject.SetActive(false);
         count = 0;
         setCountText();
         rb = GetComponent<Rigidbody>();
         win = false;
         count = 0;
     }
 
     public void startGame()
     {
         count = 0;
         win = false;
         StartClicked = true;
         backImage.gameObject.SetActive(false);
         startButton.gameObject.SetActive(false);
         hubText1.gameObject.SetActive(false);
         rb.gameObject.transform.position = new Vector3(0, 0, 0);
         pickup1.gameObject.SetActive(true);
         pickup2.gameObject.SetActive(true);
         pickup3.gameObject.SetActive(true);
         pickup4.gameObject.SetActive(true);
         pickup5.gameObject.SetActive(true);
         pickup6.gameObject.SetActive(true);
         pickup7.gameObject.SetActive(true);
         pickup8.gameObject.SetActive(true);
         pickup9.gameObject.SetActive(true);
         pickup10.gameObject.SetActive(true);
         pickup11.gameObject.SetActive(true);
         pickup12.gameObject.SetActive(true);
         pickup13.gameObject.SetActive(true);
         pickup14.gameObject.SetActive(true);
         pickup15.gameObject.SetActive(true);
         pickup16.gameObject.SetActive(true);
         rb.isKinematic = false;
         winText.gameObject.SetActive(false);
         loseText.gameObject.SetActive(false);
         countText.text = "Count: " + count;
     }
 
     void FixedUpdate()
     {
         if (win == false) {
         float moveHorizontal = Input.GetAxis("Horizontal");
         float moveVertical = Input.GetAxis("Vertical");
 
         Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVertical);
         transform.Translate(Input.acceleration.x/10, 0, Input.acceleration.z/10);
 
             rb.AddForce(movement * speed);
         }
     }
 
     void OnTriggerEnter(Collider other)
     {
         if (other.gameObject.CompareTag("Pick Up"))
         {
             count += 1;
             other.gameObject.SetActive(false);
            setCountText();
         }
         else
         {
             if (other.gameObject.CompareTag("Danger"))
             {
                 win = true;
                 rb.isKinematic = true;
                 rb.velocity = Vector3.zero;
                 loseText.gameObject.SetActive(true);
                 startButton.gameObject.SetActive(true);
                 backImage.gameObject.SetActive(true);
                 hubText1.gameObject.SetActive(true);
 
             }
         }
     }
 
     void setCountText()
     {
         countText.text = "Count: " + count.ToString();
         if (count >= 16)
         {
             win = true;
             rb.isKinematic = true;
             rb.velocity = Vector3.zero;
             winText.gameObject.SetActive(true);
             startButton.gameObject.SetActive(true);
             backImage.gameObject.SetActive(true);
             hubText1.gameObject.SetActive(true);
 
          //  if (Application.loadedLevel.Equals("Level1")) { 
             //Application.LoadLevel("Level2");
        // }else
        // {
            // if (Application.loadedLevel.Equals("Level2"))
            // {
                 Application.LoadLevel("Minigame");
            // }
        // }
         }
     }  
 }