Unity C# 脚本抛出“您尝试实例化的对象为空”错误，但仅当脚本位于预制 object 上时

Question

I have a script set up to be called by an animation event to instantiate an object. This works just fine when the script is placed on a GameObject that is already in the scene; however, it does not work when the script is placed on an object that has been instantiated into the scene.

ex: coffee brewer instantiates a coffee cup using the script (this works) --> that coffee cup then instantiates a cup sleeve (this throws error ArgumentException: The Object you want to instantiate is null.). The script is as follows:

public GameObject product;//this part is always assigned in the inspector
private GameObject leftHand;
private GameObject barista;
private GameObject rightHand;


private void Start()
{
    leftHand = GameObject.FindGameObjectWithTag("LeftHand");
    rightHand = GameObject.FindGameObjectWithTag("RightHand");
    barista = GameObject.FindGameObjectWithTag("Player");
}

public void instantiateItemInHand()
{
    
   
    if (!barista.GetComponent<BaristaController>().leftHandIsFull)//left hand isn't full
    {
        Instantiate(product, leftHand.transform) ;//put the object in the left hand
        
    }
    else if (!barista.GetComponent<BaristaController>().rightHandIsFull)//right hand isn't full
    {
        Instantiate(product, rightHand.transform);//put the object in the right hand
        
    }

}

Answer 1

This actually had to do with the animation events. For some reason, the actual events had become null during the process of copying them over to one another.