Code works in editor, but after building it doesn't.

I have created a script for a homing missile that chases you and damages you once you get hit. It works fine in the editor, but after I build it, my character does not take any damage at all.
(The missile is located in a prefab).

This is my player script:

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class Player : MonoBehaviour
5. {
6.  
7.     //Floats
8.     public float maxSpeed = 3;
9.     public float speed = 50f;
10.     public float jumpPower = 150f;
11.  
12.     //Booleans
13.     public bool grounded;
14.     public bool canDoubleJump;
15.  
16.     //Stats
17.     public float curHealth;
18.     public float max_health = 100f;
19.  
20.     //References
21.     private Rigidbody2D rb2d;
22.     private PlayerHealthSystem phs;
23.     public Transform fp;
24.  
25.  
26.  
27.     void Start()
28.     {
29.         rb2d = gameObject.GetComponent<Rigidbody2D>();
30.         phs = gameObject.GetComponent<PlayerHealthSystem>();
31.         fp = this.gameObject.transform.GetChild(3);
32.  
33.         curHealth = max_health;
34.  
35.     }
36.  
37.  
38.     void Update()
39.     {
40.  
41.         if (Input.GetAxis("Horizontal") < -0.1f)
42.         {
43.             transform.localScale = new Vector3(-0.5f, 0.5f, 0.5f);
44.  
45.             Right();
46.         }
47.  
48.         if (Input.GetAxis("Horizontal") > 0.1f)
49.         {
50.             transform.localScale = new Vector3(0.5f, 0.5f, 0.5f);
51.  
52.             Left();
53.         }
54.  
55.         if (Input.GetButtonDown("Jump"))        {
56.             if (grounded)
57.             {
58.                 rb2d.AddForce(Vector2.up * jumpPower);
59.                 canDoubleJump = true;
60.             }
61.             else
62.             {
63.  
64.                 if (canDoubleJump)
65.                 {
66.  
67.                     canDoubleJump = false;
68.                     rb2d.velocity = new Vector2(rb2d.velocity.x, 0);
69.                     rb2d.AddForce(Vector2.up * jumpPower / 1.75f);
70.  
71.                 }
72.  
73.             }
74.         }
75.  
76.         if (curHealth > max_health)
77.         {
78.             curHealth = max_health;
79.         }
80.  
81.         if (curHealth <= 0)
82.         {
83.  
84.             curHealth = 0;
85.  
86.             Die();
87.  
88.         }
89.  
90.  
91.  
92.     }
93.  
94.     void FixedUpdate()
95.     {
96.         Vector3 easeVelocity = rb2d.velocity;
97.         easeVelocity.y = rb2d.velocity.y;
98.         easeVelocity.z = 0.0f;
99.         easeVelocity.x *= 0.75f;
100.  
101.         float h = Input.GetAxis("Horizontal");
102.  
103.         /*//Fake friction / Easing the x speed of our player
104.         if (grounded)
105.         {
106.  
107.             rb2d.velocity = easeVelocity;
108.  
109.         }
110.         */
111.  
112.         //Moving the player
113.         rb2d.AddForce((Vector2.right * speed) * h);
114.  
115.         //Limiting the speed of the player
116.         if (rb2d.velocity.x > maxSpeed)
117.         {
118.             rb2d.velocity = new Vector2(maxSpeed, rb2d.velocity.y);
119.         }
120.  
121.         if (rb2d.velocity.x < -maxSpeed)
122.         {
123.             rb2d.velocity = new Vector2(-maxSpeed, rb2d.velocity.y);
124.         }
125.        
126.     }
127.  
128.     void Die()
129.     {
130.  
131.         Application.LoadLevel(Application.loadedLevel);
132.  
133.     }
134.  
135.     public void Damage(int pain)
136.     {
137.  
138.         curHealth -= pain;
139.  
140.     }
141.  
142.  
143.     public IEnumerator Knockback(float knockDur, float knockbackPwr, Vector3 knockbackDir)
144.     {
145.  
146.         float timer = 0;
147.  
148.         while (knockDur > timer)
149.         {
150.  
151.             timer += Time.deltaTime;
152.  
153.             rb2d.AddForce(new Vector3(knockbackDir.x * -100, knockbackDir.y * knockbackPwr, transform.position.z));
154.  
155.         }
156.  
157.         yield return 0;
158.  
159.     }
160.  
161.     void Right()
162.     {
163.         fp.transform.localRotation = Quaternion.Euler(0, 0, 180f);
164.     }
165.  
166.     void Left()
167.     {
168.         fp.transform.localRotation = Quaternion.Euler(0, 0, 0);
169.     }
170. }

This is my missile script:

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class Homing : MonoBehaviour
5. {
6.     private Player player;
7.  
8.     public float speed = 5;
9.     public float rotatingSpeed = 200;
10.     public int pain = 10;
11.     public GameObject target;
12.  
13.     Rigidbody2D rb;
14.  
15.     // Use this for initialization
16.     void Start()
17.     {
18.  
19.         target = GameObject.FindGameObjectWithTag("Play");
20.         player = GameObject.FindGameObjectWithTag("Play").GetComponent<Player>();
21.         rb = GetComponent<Rigidbody2D>();
22.  
23.  
24.     }
25.  
26.     // Update is called once per frame
27.     void FixedUpdate()
28.     {
29.  
30.         Vector2 point2Target = (Vector2)transform.position - (Vector2)target.transform.position;
31.  
32.         point2Target.Normalize();
33.  
34.         float value = Vector3.Cross(point2Target, transform.right).z;
35.  
36.         /*
37.         if (value > 0) {
38.  
39.                 rb.angularVelocity = rotatingSpeed;
40.         } else if (value < 0)
41.                 rb.angularVelocity = -rotatingSpeed;
42.         else
43.                 rotatingSpeed = 0;
44. */
45.  
46.         rb.angularVelocity = rotatingSpeed * value;
47.  
48.  
49.         rb.velocity = transform.right * speed;
50.  
51.  
52.     }
53.  
54.  
55.     public void OnTriggerEnter2D(Collider2D hitInfo)
56.     {
57.         if (hitInfo.tag == "Play")
58.         {
59.             player.Damage(pain);
60.         }
61.         Destroy(gameObject);
62.     }
63.  
64.  
65. }

Could anyone help me? Thanks.

 

Check the logs and see if you're getting any errors: https://docs.unity3d.com/Manual/LogFiles.html