Help needed! Unity disables all colliders for some reason

Unity Engine
,
1

Hello, when i try to play my 3D Point And Click game, all the colliders on my every object (Nodes) in the scene are disabled. I had this problem after i tried to make a door, that you can open and close with a key. Making that door somehow disabled all colliders, even after i deleted all the door scripts. Link for the tutorial i tried to use to make my door with:

I also get an error every time i to try play the game. Error in Unity:
NullReferenceException: Object reference not set to an instance of an object
Node.SetReachableNodes (Boolean set) (at Assets/Scripts/Nodes/Node.cs:51)
Node.Arrive () (at Assets/Scripts/Nodes/Node.cs:40)
GameManager.Start () (at Assets/Scripts/GameManager.cs:27).

My Node script:

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using DG.Tweening;

public abstract class Node : MonoBehaviour {

    public Transform cameraPosition;
    public List<Node> reachableNodes = new List<Node>();

    [HideInInspector]
    public Collider col;

    // Use this for initialization
    void Awake () {
        col = GetComponent<Collider>();
        col.enabled = false;
    }

    void OnMouseDown() {
        Arrive ();
    }

    public virtual void Arrive(){
        //leave existing current node
        if (GameManager.ins.currentNode != null)
            GameManager.ins.currentNode.Leave ();

         //set currentNode
        GameManager.ins.currentNode = this;
    
         //move the camera
        GameManager.ins.rig.AlignTo(cameraPosition);

         //turn off our own collider
        if (col != null)
            col.enabled = false;

         //turn on all reachable node's colliders
        SetReachableNodes(true);
    }

    public virtual void Leave(){

        //turn off all reachable node's colliders
        SetReachableNodes(false);
    }

    public void SetReachableNodes(bool set){
        foreach (Node node in reachableNodes){
            if (node.col != null) {
                if (node.GetComponent<Prerequisite> () && node.GetComponent<Prerequisite> ().nodeAccess) {
                    if (node.GetComponent<Prerequisite> ().Complete) {
                        node.col.enabled = set;
                    }
                } else {
                    node.col.enabled = set;
                }

            }
        }   
    }

}

GameManager Script:

using UnityEngine;
using System.Collections;

public class GameManager : MonoBehaviour {

    public static GameManager ins;
    public IVCanvas ivCanvas;
    public ObsCamera obsCamera;
    public InventoryDisplay invDisp;

    public Node startingNode;

    [HideInInspector]
    public Node currentNode;
    public Item itemHeld;

    public CameraRig rig;

    //singleton
    void Awake() {
        ins = this;
        ivCanvas.gameObject.SetActive(false);
        obsCamera.gameObject.SetActive (false);
    }
   
    void Start(){
        startingNode.Arrive ();       
    }

    void Update() {
        if (Input.GetMouseButtonDown(1) && currentNode.GetComponent<Prop>() != null){
            if (ivCanvas.gameObject.activeInHierarchy) {
                ivCanvas.Close();
                return;
            }
            if (obsCamera.gameObject.activeInHierarchy) {
                obsCamera.Close();
                return;
            }
            currentNode.GetComponent<Prop>().loc.Arrive();
        }   
    }
       
}
2

You appear to have a null node in reachableNodes. How do you populate the lists?

Maybe check if node is null and then check if node.col is null like: (Node.cs line 51)

if (node != null && node.col != null) {

Is it even okay to have null nodes in your case? If so, did you plan on just checking for null and skipping them? Asking because there is not else statement after that null check.

3

As for disabling colliders, isn’t that your fault?

// Use this for initialization
    void Awake () {
        col = GetComponent<Collider>();
        col.enabled = false;
    }