SendMessage/Object Reference error

So, I have two bits of code. One calls to another script to do something, and that script… Does something.

My error is that this:

void OnTriggerEnter(Collider Col){
		if (inventory.charge == 4) {
			transform.FindChild ("door").SendMessage ("DoorCheck");
			if (GameObject.Find ("chargeHUDGUI")) {
				Destroy (GameObject.Find ("chargeHUDGUI"));
				doorlight.color = Color.green;
			}
		} else if(inventory.charge > 0 && inventory.charge < 4){
			TextHints.SendMessage("I think it needs more power!" , "ShowHint", UnityEngine.SendMessageOptions);
			
		} else {
				AudioSource.PlayClipAtPoint (lockedsound, transform.position);
				Col.gameObject.SendMessage("HUDon");
			TextHints.SendMessage("This Door is locked, I need to power it!" , "ShowHint", UnityEngine.SendMessageOptions);
			}

On TextHints.SendMessage, needs the string (The first line of text in the SendMessage) and the object, however, I’m not aware of what I need for those. Here’s the script it’s calling to:

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
public class TextHints : MonoBehaviour {
	Text text;
	public float timer = 0.0f;
	// Use this for initialization
	void Start () {
		text = GetComponent<Text>();
	}	
	// Update is called once per frame

	void Update () {
		if (text.enabled) {
			timer += Time.deltaTime;
		}
		if (timer >= 4) {
			text.enabled = false;
			timer = 0.0f;
		}
	}
	void ShowHint(string message){

		text.text = message;
		if(!text.enabled){
			text.enabled = true;
	}
}
}

Seems you have the parameters mixed up. Try swapping the methodname and the value, like this:

 TextHints.SendMessage("ShowHint", "This Door is locked, I need to power it!", UnityEngine.SendMessageOptions);

http://docs.unity3d.com/ScriptReference/GameObject.SendMessage.html

  public void SendMessage(string methodName, object value = null, SendMessageOptions options = SendMessageOptions.RequireReceiver);
  • methodName: The name of the method to
    call.

  • value: An optional parameter. value to pass to the called method.

  • options: Should an error be raised if
    the method doesn’t exist on the
    target object?