Restarting Unity Project - Now it doesn't run

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#1

I saved my progress after “Dependency Inversion With Interfaces” with the game running just fine. Now, when restarting later with no changes made, I am getting errors and the character will not move.

Errors:

NullReferenceException: Object reference not set to an instance of an object
RPG.Movement.Mover.StartMoveAction (UnityEngine.Vector3 destination) (at Assets/Scripts/Movement/Mover.cs:28)
RPG.Control.PlayerController.InteractWithMovement () (at Assets/Scripts/Control/PlayerController.cs:43)
RPG.Control.PlayerController.Update () (at Assets/Scripts/Control/PlayerController.cs:15)

NullReferenceException: Object reference not set to an instance of an object
RPG.Combat.Fighter.Attack (RPG.Combat.CombatTarget combatTarget) (at Assets/Scripts/Combat/Fighter.cs:36)
RPG.Control.PlayerController.InteractWithCombat () (at Assets/Scripts/Control/PlayerController.cs:28)
RPG.Control.PlayerController.Update () (at Assets/Scripts/Control/PlayerController.cs:14)

I have gone through the videos and made sure the script was the same, which it is. I cannot figure out why I am getting these errors.

Mover.cs:

using System.Collections;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using UnityEngine;
using UnityEngine.AI;
using RPG.Core;

namespace RPG.Movement
{
    public class Mover : MonoBehaviour, IAction
    {
        [SerializeField] Transform target;

        NavMeshAgent navMeshAgent;

        private void Start()
        {
            navMeshAgent = GetComponent<NavMeshAgent>();
        }

        private void Update()
        {
            UpdateAnimator();
        }

        public void StartMoveAction(Vector3 destination)
        {
            GetComponent<ActionScheduler>().StartAction(this);
            MoveTo(destination);
        }


        public void MoveTo(Vector3 destination)
        {
            navMeshAgent.destination = destination;
            navMeshAgent.isStopped = false;
        }

        public void Cancel()
        {
            navMeshAgent.isStopped = true;
        }

        private void UpdateAnimator()
        {
            Vector3 velocity = navMeshAgent.velocity;
            Vector3 localVelocity = transform.InverseTransformDirection(velocity);
            float speed = localVelocity.z;
            GetComponent<Animator>().SetFloat("forwardSpeed", speed);
        }
    }
}

Fighter.cs:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using RPG.Movement;
using RPG.Core;

namespace RPG.Combat
{
    public class Fighter : MonoBehaviour, IAction
    {
        [SerializeField] float weaponRange = 2f;

        Transform target;

        private void Update()
        {
            if (target == null) return;

            if (!GetIsInRange())
            {
                GetComponent<Mover>().MoveTo(target.position);
            }
            else
            {
                GetComponent<Mover>().Cancel();
            }
        }

        private bool GetIsInRange()
        {
            return Vector3.Distance(transform.position, target.position) < weaponRange;
        }

        public void Attack(CombatTarget combatTarget)
        {
            GetComponent<ActionScheduler>().StartAction(this);
            target = combatTarget.transform;
        }

        public void Cancel()
        {
            target = null;
        }
    }
}

IAction.cs:

using RPG.Core;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace RPG.Core
{
    public interface IAction
    {
        void Cancel();
    }
}

ActionScheduler.cs:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace RPG.Core
{
    public class ActionScheduler : MonoBehaviour
    {
        IAction currentAction;

        public void StartAction(IAction action)
        {
            if (currentAction == action) return;
            if (currentAction != null)
            {
                currentAction.Cancel();
            }
            currentAction = action;
        }
    }
}

PlayerController.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System;
using RPG.Movement;
using RPG.Combat;

namespace RPG.Control
{
    public class PlayerController : MonoBehaviour
    {
        private void Update()
        {
            if(InteractWithCombat()) return;
            if (InteractWithMovement()) return;
        }

        private bool InteractWithCombat()
        {
            RaycastHit[] hits = Physics.RaycastAll(GetMouseRay());
            foreach (RaycastHit hit in hits)
            {
                CombatTarget target = hit.transform.GetComponent<CombatTarget>();
                if (target == null) continue;

                if (Input.GetMouseButtonDown(0))
                {
                    GetComponent<Fighter>().Attack(target);
                }
                return true;
            }
            return false;
        }

        private bool InteractWithMovement()
        {
            RaycastHit hit;
            bool hasHit = Physics.Raycast(GetMouseRay(), out hit);
            if (hasHit)
            {
                if (Input.GetMouseButton(0))
                {
                    GetComponent<Mover>().StartMoveAction(hit.point);
                }
                return true;
            }
            return false;
        }

        private static Ray GetMouseRay()
        {
            return Camera.main.ScreenPointToRay(Input.mousePosition);
        }
    }
}

FollowCamera.cs:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UIElements;

namespace RPG.Core
{
    public class FollowCamera : MonoBehaviour
    {
        [SerializeField] Transform target;

        void LateUpdate()
        {
            transform.position = target.position;
        }
    }
}
#2

Check your Cursor Mapping in PlayerController. Enums might have gotten reset and you might not have the movement and combat one anymore.

#3

If you are meaning the namespaces, they are included in the PlayerController script. The only thing I think I may have done before saving, was to click reset on the Player transform in the Inspector panel. I still cannot get this fixed.

#4

Both null reference exceptions are referring to the first line of each of the methods I posted.

GetComponent<ActionScheduler>().StartAction(this);

It appears that your Player doesn’t have an ActionScheduler component attached. It’s possible that the scene or player prefab didn’t save correctly when you restarted Unity.

1 Like
#5

That’s exactly what appears to have happened. I can’t believe I didn’t notice the script was no longer attached to the Player. Thank you so much for the help.

#6

It happens sometimes.

1 Like
#7

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