Box Collider Trigger not working

I set up an empty GameObject and attached a Box Collider as a Trigger (2D Game).
Afterwards i attached the following script to the GameObject:

using UnityEngine;
using System.Collections;

public class boxSideCollider : MonoBehaviour {

	void OnTriggerEnter(Collider other){
		Debug.Log ("Enter");
		GameObject player = GameObject.FindGameObjectWithTag("Player");

Neither the logtext nor the other code appears/works when the character is entering the zone.

Can somebody help me? Thanks!

Found the answer here: Unity - Scripting API: Collider2D.OnTriggerEnter2D(Collider2D)