iOS Game Center [Achievement ID not found]

Please can someone help me with my Progress Achievement problem? I don’t know, Game Center Authenticates, but I’m getting Achievement ID not found error message.

using UnityEngine;
using System.Collections;

public class scoreHandler : MonoBehaviour {

	private int _score = 0;

     private bool Rank_2 = false; 
	private bool Rank_3 = false;
     
     public GameObject Cube;

     public string leaderboardID = "com.nurlan.lockedup";
	public string AchievementID2 = "lockedup_achievement_1";
	public string AchievementID3 = "lockedup_achievement_2";

         
                void Update () {


				if (_score >= 7 && !Rank_2) {
						Rank_2 = true;
						Cube.SetActive (true);
			            Ranked ();
						this.GetComponent<playSound> ().PlaySound ("rank");
				}
				if (_score == 8) {
						Cube.SetActive (false);
						Debug.Log ("Rank2");

				}


				if (_score >= 14 && ! Rank_3) {
						Rank_3 = true;
						Cube.SetActive (true);
                            Ranked ();
						this.GetComponent<playSound> ().PlaySound ("rank");
				}
				if (_score == 15) {
						Cube.SetActive (false);
						Debug.Log ("Rank3");
				}


           private void Ranked ()
	            {
				if (Social.localUser.authenticated) {
			Social.ReportProgress (AchievementID2, 100, HandleProgressReported);
				}
		}

	      private void HandleProgressReported (bool a_success)
	  {
		Debug.Log("*** HandleProgressReported: success = " + a_success);
	}
}

Achievement ID not found
UnityEngine.Social:ReportProgress(String, Double, Action`1)

Thank you.

Hi. I had a similar problem for my android build. I managed to fix it by activating Play Games platform. In order to do so I had to run this line of code right when my game starts: PlayGamesPlatform.Activate();

It should be called only once so I had it done like this:

static bool once = false;

void Start()
{
	if(once == false)
	{
		 PlayGamesPlatform.Activate();
		 once = true;
	}
}

I hope this helps!