NullReferenceException while executing 'started' callbacks of...

Hi, I am getting this error after I press the relative key:
NullReferenceException while executing 'started' callbacks of 'DefaultControls/SelectOption2[/Keyboard/2]'
UnityEngine.InputSystem.LowLevel.<>c__DisplayClass7_0:<set_onUpdate>b__0(NativeInputUpdateType, NativeInputEventBuffer*)
UnityEngineInternal.Input.NativeInputSystem:NotifyUpdate(NativeInputUpdateType, IntPtr) (at /Users/builduser/buildslave/unity/build/Modules/Input/Private/Input.cs:120)

Code is the following. I am just using Invoke Unity Events, with the buttons set as Pass Through > Button > Press Only. If I don't put ctx.started in the if statement I get a NullRef even for "performed" and "canceled".

I am just trying to make a simple button for my prototype, for heaven's sake. I HAVE to use the new input system for unrelated reasons. Thanks.

Code (CSharp):

1. using UnityEngine;
2.  
3. using UnityEngine.InputSystem;
4. using static UnityEngine.InputSystem.InputAction;
5. using System;
6. using System.Linq;
7. using DialogueEditor;
8.  
9. public class InputHandler : MonoBehaviour
10. {
11.     private PlayerInput input;
12.     private ThirdPersonMovement playerMovement;
13.     private ConversationHandler conversation;
14.     private int playerIndex;
15.  
16.     private void Awake()
17.     {
18.         input = GetComponent<PlayerInput>();
19.         conversation = ConversationHandler.Instance;
20.  
21.         //Assign the instance of PlayerInput to the correct player
22.         var index = input.playerIndex;
23.         var playerMovementScripts = FindObjectsOfType<ThirdPersonMovement>();
24.         playerMovement = playerMovementScripts.FirstOrDefault(m => m.GetComponentInParent<Index>().GetIndex() == index);
25.  
26.         playerIndex = playerMovement.GetComponentInParent<Index>().GetIndex();
27.     }
28.  
29.     //Move the player
30.     public void OnMove(CallbackContext ctx) { if(playerMovement != null) { playerMovement.InputVector = new Vector3(ctx.ReadValue<Vector2>().x, 0, ctx.ReadValue<Vector2>().y); } }
31.  
32.     //Input selected option
33.     public void OnSelectOption1(CallbackContext ctx) { if(ctx.started && conversation.selectionSentences != null && conversation.selectionSentences.Count > 0) { SelectSentence(0); } }
34.     public void OnSelectOption2(CallbackContext ctx) { if(ctx.started && conversation.selectionSentences != null && conversation.selectionSentences.Count > 1) { SelectSentence(1); } }
35.     public void OnSelectOption3(CallbackContext ctx) { if(ctx.started && conversation.selectionSentences != null && conversation.selectionSentences.Count > 2) { SelectSentence(2); } }
36.  
37.     //Send selected sentence and index
38.     private void SelectSentence(int n) { conversation.selectedSentences.Add(new Tuple<SpeechNode, int>(conversation.selectionSentences[n].Dialogue, playerIndex)); }
39. }
40.  

 

The error messages *after* the log for the NRE is the actual exception dump. The initial message only gives context for the exception but the NRE happens inside the callback.

The "two messages logged for one error" behavior probably isn't the best and probably could use some tweaking.

 

Any idea on how I could go around solving it? It's a prototype, I just need a button press functionality... If I need to change some code I'd be down for that. Thanks

 

Wait, do you mean to say that the actual error is not that, but a second error I might be getting? Because I am getting another error, that doesn't have anything to do with the input system, or at least I think:

NullReferenceException: Object reference not set to an instance of an object
InputHandler.OnSelectOption2 (UnityEngine.InputSystem.InputAction+CallbackContext ctx) (at Assets/Scripts/Player Characters/InputHandler.cs:33)
UnityEngine.Events.InvokableCall`1[T1].Invoke (T1 args0) (at /Users/builduser/buildslave/unity/build/Runtime/Export/UnityEvent/UnityEvent.cs:221)
UnityEngine.Events.UnityEvent`1[T0].Invoke (T0 arg0) (at /Users/builduser/buildslave/unity/build/Runtime/Export/UnityEvent/UnityEvent/UnityEvent_1.cs:58)
UnityEngine.InputSystem.Utilities.DelegateHelpers.InvokeCallbacksSafe[TValue] (UnityEngine.InputSystem.Utilities.InlinedArray`1[System.Action`1[TValue]]& callbacks, TValue argument, System.String callbackName, System.Object context) (at Library/PackageCache/com.unity.inputsystem@1.0.0/InputSystem/Utilities/DelegateHelpers.cs:51)
UnityEngine.InputSystem.LowLevel.<>c__DisplayClass7_0:<set_onUpdate>b__0(NativeInputUpdateType, NativeInputEventBuffer*)
UnityEngineInternal.Input.NativeInputSystem:NotifyUpdate(NativeInputUpdateType, IntPtr) (at /Users/builduser/buildslave/unity/build/Modules/Input/Private/Input.cs:120)

 

Yup, that's what I meant. The first error is the input system saying "hey, an exception occurred in a callback" and the second error is the actual exception. The actual NRE comes from InputHandler.cs@33 in your case.

 

So, how do i solve it?

 

Sorry, if I'm late for to party.
It depends on the error you're getting. If you still need help, tell what error you're getting, so I can try to help.

 

im getting an error that says "NullReferenceException while executing 'performed' callbacks of 'Player/Jump[/DualShock4GamepadHID/buttonSouth]'" how can i fix this

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.InputSystem;
5.  
6. public class PlayerController : MonoBehaviour
7. {
8.     private float moveInput;
9.     public float speed;
10.     public float jumpForce;
11.  
12.     public float checkRadius;
13.     public LayerMask groundCheck;
14.     public Transform playerPos;
15.  
16.     private Rigidbody2D rb;
17.  
18.     private bool facingRight = true;
19.  
20.     void Start()
21.     {
22.         rb = GetComponent<Rigidbody2D>();
23.     }
24.     void Update()
25.     {
26.         if (!facingRight && moveInput > 0)
27.         {
28.             Flip();
29.         }
30.         if (facingRight && moveInput < 0)
31.         {
32.             Flip();
33.         }
34.     }
35.  
36.     void FixedUpdate()
37.     {
38.         rb.velocity = new Vector2(moveInput * speed, rb.velocity.y);
39.     }
40.  
41.     void Flip()
42.     {
43.         facingRight = !facingRight;
44.         Vector3 Scaler = transform.localScale;
45.         Scaler.x *= -1;
46.         transform.localScale = Scaler;
47.     }
48.  
49.     public void Move(InputAction.CallbackContext context)
50.     {
51.         moveInput = context.ReadValue<Vector2>().x;
52.     }
53.  
54.     public void Jump(InputAction.CallbackContext context)
55.     {
56.         if (context.performed && IsGrounded())
57.         {
58.             rb.velocity = new Vector2(rb.velocity.x, jumpForce);
59.         }
60.  
61.         if (context.canceled && rb.velocity.y > 0f)
62.         {
63.             rb.velocity = new Vector2(rb.velocity.x, rb.velocity.y * 0.7f);
64.         }
65.     }
66.  
67.     private bool IsGrounded()
68.     {
69.         return Physics2D.OverlapCircle(playerPos.position, checkRadius, groundCheck);
70.     }
71. }

 

Hey dude. I just got this same error and it was pretty confusing. I think its meant to mean more detail but its misleading.

My bug had nothing to do with the button that I pressed, but instead was telling me that it happened as a result of the function called(like an error in the function the button started).

If your bug is similar to mine, the first place to look would be " public void Jump"

I would make sure everything is returning a value. Try removing code from that function and adding it back one piece at a time. Also note that this error might not be in the jump function but could be in a function called from the jump function. Maybe your "IsGrounded" function has an error. Or maybe your variable "rb" is returning null.

BUT IF I WAS TO STAB IN THE DARK....looks like youre trying to return a bool when youre actually returning colliders in IsGrounded. If im right, then you are getting an error in jump because it was called after your button was pressed as a chain reaction. Hope it helps.

 

I got the error because I was subbed to the same input action on 2 running scripts.

 

For me, Unity just needed restarting.