Roll-ball tutorial can't pick up cube

Ok, so first off, I’m embarrassed I even have to ask this. I pride myself on my good coding, but I can’t seem to figure out what’s wrong. The ball just rolls right through the cube without picking it up. Here’s my code:

using UnityEngine;
using System.Collections;

public class PlayerController : MonoBehaviour {

	public float speed;

	void FixedUpdate()
	{
		float moveHorizontal = Input.GetAxis ("Horizontal");
		float moveVertical = Input.GetAxis ("Vertical");

		Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);

		rigidbody.AddForce(movement * speed * Time.deltaTime);
	}

	void OnTriggerEnter(Collider other)
	{
		if(other.gameObject.tag == "PickUp")
			other.gameObject.SetActive(false);
		
		
	}
}

Fixed it! Tried building and running it, and it worked! Strange.

Assuming you’ve tagged all pickup gameObjects, you simply need to make sure you enable istrigger on your spinning cube prefab. OnTriggerEnter will only pass true when your player object comes into contact with other triggers. If you look at your cube prefab then you will see a check box in the editor to enable triggering.