Resolved CharacterController NullReferenceException only in Windows Build

Hi,

I've been running into an issue when attempting to build my game.

The game runs perfectly in the Unity Editor on both Windows and MacOS. The MacOS build of the game also runs perfectly without issue. However, for some reason in the Windows standalone build, when I enter my main game scene I encounter a NullReferenceException when attempting to access the CharacterController on my player in order to move it.

NullReferenceException: Object reference not set to an instance of an object
at PlayerController.Update () [0x0004c] in ...\Reef Rally 2019.2.7\Assets\Scripts\PlayerController.cs:111

I have attached the editor log from the most recent build run.

Here is my PlayerController script where the error is originating. I should mention that the motion controller referenced within the script should have no effect on ability to find the CharacterController.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using Leap;
5.  
6. /*
7.     This script controls the movement mechancics of the player when using both a keyboard or motion controller. The main function of this script
8.     determines whether or not the player is dead or alive. Then, depending on if a hand is detected by the controller it decides whether the game will be
9.     controlled by the keyboard or by the motion controller.
10. */
11.  
12. public class PlayerController : MonoBehaviour
13. {
14.     //Define External Scripts
15.     [HideInInspector] HandController handPosition;
16.     [HideInInspector] public CharacterController controller;
17.     [HideInInspector] public GameplayController gameplayController;
18.  
19.     //Define GameObjects
20.     [HideInInspector] public GameObject player;
21.     [HideInInspector] private GameObject mainCamera;
22.  
23.     //Define player states
24.     [HideInInspector] public enum State { None, Alive, Dead };
25.     [HideInInspector] public State playerState;
26.  
27.     //Add ranged slider to inspector for camera distance from player
28.     [Range(0.0f, 20.0f)] [SerializeField] float cameraOffsetZ;
29.     [Range(-5.0f, 5.0f)] [SerializeField] float cameraOffsetY;
30.  
31.     //Define Leap Motion Interaction Box Vector
32.     Vector normalized;
33.  
34.     //Define input axis variables
35.     float leapHorizontal;
36.     float leapVertical;
37.     float horizontal;
38.     float vertical;
39.  
40.     //Create inspector input for Movement variables
41.     [SerializeField] float controlSpeed = 10f; //Speed in m/s^-1
42.     //[SerializeField] float leapControlSpeed = 15f; //Speed in m/s^-1
43.     [SerializeField] public float forwardVelocity = 5.0f;
44.     [SerializeField] float waterGravity = 3.0f;
45.     [SerializeField] float leapMovementScale = 1.5f;
46.  
47.     //Throw is 1 > -1 offset from centre of controller
48.     float xThrow;
49.     float yThrow;
50.  
51.     //Create inspector input for Player Rotation Variables
52.     private float controlPitchFactor = -30f;
53.     private float controlRollFactor = -20f;
54.     private float leapRotationFactor = 50;
55.  
56.     //Define Character postion as Vector3
57.     Vector3 characterPos;
58.  
59.     //Create floats for player movement restrictions
60.     [SerializeField] public float xClamp = 4f;
61.     [SerializeField] public float yClamp = 3f;
62.     private float xLeapClampMin = -3.5f;
63.     private float xLeapClampMax = 3.5f;
64.     private float yLeapClampMin = 1f;
65.     private float yLeapClampMax = 6f;
66.  
67.     private void Awake()
68.     {
69.         //Access Game Objects
70.         mainCamera = GameObject.FindGameObjectWithTag("MainCamera");
71.  
72.         //Access External Scripts
73.         handPosition = GameObject.FindGameObjectWithTag("HandController").GetComponent<HandController>();
74.         gameplayController = mainCamera.GetComponent<GameplayController>();
75.     }
76.  
77.     // Start is called before the first frame update
78.     void Start()
79.     {
80.         //Set Player to dead, is change to alive by GameplayController after start delay
81.         gameplayController.playerState = GameplayController.State.Dead;
82.  
83.         player = GameObject.FindGameObjectWithTag("Player");
84.  
85.         cameraOffsetY = 0.8f;
86.         cameraOffsetZ = 6f;
87.     }
88.  
89.     // Update is called once per frame
90.     void Update()
91.     {
92.         //Get HandController Data from current frame
93.         Frame frame = handPosition.GetFrame();
94.         //Define hand as most prominent hand detected in the frame by Leap Motion
95.         Hand hand = frame.Hands.Frontmost;
96.  
97.         controller = player.GetComponent<CharacterController>();
98.         //controller.detectCollisions = false;
99.  
100.         AccessInputVariables(frame, hand);
101.  
102.         //Run if player is not Dead
103.         if (gameplayController.playerState != GameplayController.State.Dead)
104.         {
105.             //Move player forward at specified speed m/s
106.             controller.Move((Vector3.forward * forwardVelocity) * Time.deltaTime);
107.             controller.Move((Vector3.down * waterGravity) * Time.deltaTime);
108.  
109.             //If hand is detected by Motion Controller
110.             if (hand.IsValid)
111.             {
112.                 UseHandControls(frame, hand, leapHorizontal, leapVertical);
113.             }
114.             //else if no hand is detected
115.             else
116.             {
117.                 UseKeyControls(horizontal, vertical);
118.             }
119.         }
120.  
121.         //Camera follows the player
122.         CameraFollow();
123.  
124.     }
125.  
126.     private void AccessInputVariables(Frame frame, Hand hand)
127.     {
128.         //Access Leap Motion Interaction Box
129.         normalized = frame.InteractionBox.NormalizePoint(hand.PalmPosition, true) * 2;
130.  
131.         //Access input axis and Interaction Box axis
132.         leapHorizontal = normalized.x - 1;
133.         leapVertical = normalized.y - 1;
134.         horizontal = Input.GetAxis("Horizontal");
135.         vertical = Input.GetAxis("Vertical");
136.     }
137.  
138.     public void UseKeyControls(float horizontal, float vertical)
139.     {
140.         xPlayerMovement(controlSpeed, horizontal);
141.         yPlayerMovement(controlSpeed, vertical);
142.         PlayerRotation(horizontal, vertical);
143.     }
144.  
145.     public void UseHandControls(Frame frame, Hand hand, float horizontal, float vertical)
146.     {
147.         //Interaction Box Hand Controls
148.         //xPlayerMovement(leapControlSpeed, horizontal);
149.         //yPlayerMovement(leapControlSpeed, vertical);
150.         //PlayerRotation(horizontal, vertical);
151.  
152.         //Legacy Hand Controls
153.         PlayerMovement(hand);
154.         PlayerRotation(hand);
155.     }
156.  
157.     private void CameraFollow()
158.     {
159.         //Define characterPos as current world position of the character model
160.         characterPos = player.transform.position;
161.  
162.         //Set camera position to player position with a defined offset behind the player
163.         mainCamera.transform.position = new Vector3(characterPos.x, characterPos.y + cameraOffsetY, characterPos.z - cameraOffsetZ);
164.     }
165.  
166.     private void xPlayerMovement(float SpeedFactor, float inputAxis)
167.     {
168.         //Horizontal input from controller/keyboard - joystick/a-d
169.         xThrow = inputAxis;
170.  
171.         //Time.deltaTime = time passed since last frame. Allows for constant velocity with varying fps distance = speed x Velocity
172.         float xOffset = xThrow * controlSpeed * Time.deltaTime;
173.  
174.         //Change player x-axis position with offset included
175.         float xPos = player.transform.localPosition.x + xOffset;
176.  
177.         //Restrict how far player can move
178.         xPos = Mathf.Clamp(xPos, -xClamp, xClamp);
179.  
180.         //Change position on x-axis without altering y and z axes
181.         player.transform.localPosition = new Vector3(xPos, player.transform.localPosition.y, player.transform.localPosition.z);
182.     }
183.  
184.     private void yPlayerMovement(float SpeedFactor, float inputAxis)
185.     {
186.         //Vertical input from controller/keyboard - joystick/w-s
187.         yThrow = inputAxis;
188.  
189.         //Time.deltaTime = time passed since last frame. Allows for constant velocity with varying fps distance = speed X Velocity
190.         float yOffset = yThrow * SpeedFactor * Time.deltaTime;
191.  
192.         //Change player y-axis position with offset included
193.         float yPos = player.transform.localPosition.y + yOffset;
194.  
195.         //Restrict how far player can move
196.         yPos = Mathf.Clamp(yPos, -yClamp, yClamp);
197.  
198.         //Change position on y-axis without altering y and z axes
199.         player.transform.localPosition = new Vector3(player.transform.localPosition.x, yPos, player.transform.localPosition.z);
200.     }
201.  
202.     private void PlayerRotation(float xRotation, float yRotation)
203.     {
204.         //Define Roll and Pitch multiplied by their control factor
205.         float roll = xRotation * controlRollFactor;
206.         float pitch = yRotation * controlPitchFactor;
207.  
208.         //Transform rotation based on factored proportions in relation to position of player
209.         player.transform.localRotation = Quaternion.Euler(pitch, 0, roll); //x, y, z
210.     }
211.  
212.     private void PlayerMovement(Hand hand)
213.     {
214.         Vector3 getHandPosition = handPosition.transform.TransformPoint(hand.PalmPosition.ToUnityScaled());
215.  
216.         //Define X and Y axes of hand position and mulitply by leapMovementScale
217.         float xPosHand = getHandPosition.x * leapMovementScale;
218.         float yPosHand = getHandPosition.y * leapMovementScale;
219.  
220.         //Set clamps for hand position
221.         float clampedXPos = Mathf.Clamp(xPosHand, xLeapClampMin, xLeapClampMax);
222.         float clampedYPos = Mathf.Clamp(yPosHand, yLeapClampMin, yLeapClampMax);
223.  
224.         //Transform position of Player with position of user's hand
225.         player.transform.position = new Vector3(clampedXPos, clampedYPos, player.transform.position.z);
226.     }
227.  
228.     private void PlayerRotation(Hand hand)
229.     {
230.         float pitch = hand.Direction.Pitch * -leapRotationFactor;
231.         float roll = hand.PalmNormal.Roll * leapRotationFactor;
232.  
233.         player.transform.rotation = Quaternion.Euler(pitch, 0, roll);
234.     }
235. }
236.  
237.  

This is my first time posting on these threads so apologies if I have not uploaded everything in the correct format.

 

You probably should put your file path in the post as everyone now knows you are in your 3rd year in college

NullReferenceExceptions are a pain - especially when it works in the editor and not on a certain build. I had this problem many times and EVERY SINGLE TIME it was because I was using one of the Find methods like you are. Apparently, different platforms don't maintain the same order of GameObjects... For instance, if you have two objects that have the same tag and you do the statement in line 73, FindGameObjectWithTag, it may pick up the 1st object in your list in the Unity Editor but on a different platform (Windows, XBOX, etc), it may pick up the 2nd one. If you don't have the right setup on that object, you may receive this error.

Not sure if that's your problem but just check and see if you have multiple objects with the same tag unintentionally (maybe you duplicated an object to test something?).

 

Hey, thanks for taking the time to respond!

I managed to eventually trace it back to exactly how you had described. I had moved my the colliders from my character to a separate object within the parent and I had left the same tag on this new child object as the parent. And then yes, for whatever reason in the way the platform builders work, the Windows build appeared to go directly for the child object as opposed to the parent which contained the characterController.

 

No problem - I'm glad you were able to solve it!