How do I fix a NullReferenceException

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I am getting a NullReferenceException: object reference not set to an instant of an object.

I am a beginner and had learned this through a video. All the code is good but the null appears on the line:

"playerRigidBody.MovePosition(transform.position + movement);"

I have tried for several hours to write the code but have not nailed it. I do need help.

C#

using UnityEngine;
using System.Collections;

public class CharacterMovement : MonoBehaviour 

{
public float speed = 6f;		//The speed that the player will move
public float turnSpeed = 60f;		//The speed at which the character turns
public float turnSmoothing = 15f;		//The turns rate of smoothness
	
private Vector3 movement;		//x,y,z movement
private Vector3 turning;		//x,y,z, turning
private Animator anim;			//Animator variable
private Rigidbody playerRigidBody;//Game objects act under control of physics

	void awake()
	{
		//Get references
		playerRigidBody = GetComponent<rigidbody>();
		anim = GetComponent<animator>();

	}
	
	void FixedUpdate()
	{
		//Store Input Axis
		float lh = Input.GetAxisRaw ("Horizontal");
		float lv = Input.GetAxisRaw ("Vertical");
		
		Move (lh, lv);
		Animating (lh, lv);

	}
	void Move (float lh, float lv)
	{
		//Move the Player
		movement.Set (lh, 0f, lv);
		movement = movement.normalized * speed * Time.deltaTime;
		playerRigidBody.MovePosition(transform.position + movement);

		
		if (lh != 0f || lv != 0f) 

		{
			Rotating (lh, lv);
		}
	}
	
	void Rotating(float lh, float lv)
		
	{
		Vector3 targetDirection = new Vector3 (lh, 0f, lv);
		Quaternion targetRotation = Quaternion.LookRotation (targetDirection, Vector3.up);
		Quaternion newRotation = Quaternion.Lerp (GetComponent <rigidbody>().rotation, targetRotation, turnSmoothing * Time.deltaTime); 
		GetComponent<rigidbody>(). MoveRotation(newRotation);
	}
	
	void Animating (float lh, float lv)
		
	{
		bool running = lh != 0f || lv != 0f;
		anim.SetBool ("IsRunning", running);
	}
	
}</rigidbody></rigidbody></animator></rigidbody>

Posted 30-Sep-15 20:28pm

Member 12024660

Updated 30-Sep-15 20:33pm

Ralf Meier

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This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2015-09-30T20:46:00

This is one of the most common problems we get asked, and it's also the one we are least equipped to answer, but you are most equipped to answer yourself.

Let me just explain what the error means: You have tried to use a variable, property, or a method return value but it contains null - which means that there is no instance of a class in the variable.
It's a bit like a pocket: you have a pocket in your shirt, which you use to hold a pen. If you reach into the pocket and find there isn't a pen there, you can't sign your name on a piece of paper - and you will get very funny looks if you try! The empty pocket is giving you a null value (no pen here!) so you can't do anything that you would normally do once you retrieved your pen. Why is it empty? That's the question - it may be that you forgot to pick up your pen when you left the house this morning, or possibly you left the pen in the pocket of yesterdays shirt when you took it off last night.

We can't tell, because we weren't there, and even more importantly, we can't even see your shirt, much less what is in the pocket!

Back to computers, and you have done the same thing, somehow - and we can't see your code, much less run it and find out what contains null when it shouldn't.
But you can - and Visual Studio will help you here. Run your program in the debugger and when it fails, VS will show you the line it found the problem on. You can then start looking at the various parts of it to see what value is null and start looking back through your code to find out why. So put a breakpoint at the beginning of the method containing the error line, and run your program from the start again. This time, VS will stop before the error, and let you examine what is going on by stepping through the code looking at your values.

But we can't do that - we don't have your code, we don't know how to use it if we did have it, we don't have your data. So try it - and see how much information you can find out!

Member 11428137 · Answer 2 · 2015-09-30T20:46:00

It looks like you may have two problems here.
First is your awake method. According to the API documentation, the method should be Awake with a capital A. C# is case sensitive, so it won't be calling your awake method which initializes playerRigidBody.

The second thing I can see is that in the API documentation, it says that transform will be null if there isn't one attached. I can't see anywhere where you have set transform to anything.

Naveen.Sanagasetti · Answer 3 · 2015-09-30T23:02:00

Solution 3

Almost all developers may face this error once in his/her development life time. The main reason of this is, if you try to assign null value to some object or calling control using null value etc..

If you want to resolve this, the best practice is check the null case before doing action.

Posted 30-Sep-15 23:02pm

Naveen.Sanagasetti

How do I fix a NullReferenceException

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