# Help with level selector
**URL:** https://discussions.unity.com/t/help-with-level-selector/664139
**Category:** Scripting
**Tags:** Scripting
**Created:** [May 9, 2017, 4:03pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139 "2017-05-09T16:03:16Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 9, 2017, 4:03pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/1 "2017-05-09T16:03:16Z")
Hello
I am making a level selector that you can unlock levels on and when I try to unlock level 3, I get an error in the console. The error is:
NullReferenceException: Object reference not set to an instance of an object
GameManager.CompleteLevel () (at Assets/Scripts/GameManager.cs:19)
EndTrigger.OnTriggerEnter () (at Assets/Scripts/EndTrigger.cs:9)
If you need me to give you any code, just ask.
Thanks, Hayden
---
### Author:  [@johne5](https://discussions.unity.com/u/johne5)
#### Post date: [May 9, 2017, 4:05pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/2 "2017-05-09T16:05:32Z")
NullReferenceException means you didn’t set the value. look at GameManager.cs: line 19 to see what it’s complaining about
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 10, 2017, 3:49pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/3 "2017-05-10T15:49:41Z")
This is line 19
gameManager.WinLevel();
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 10, 2017, 3:50pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/4 "2017-05-10T15:50:16Z")
And this is WinLevel
public void WinLevel()
{
Debug.Log(“LEVEL WON”);
PlayerPrefs.SetInt(“levelReached”, levelToUnlock);
SceneManager.LoadScene(nextLevel);
}
---
### Author:  [@WarmedxMints\_1](https://discussions.unity.com/u/WarmedxMints_1)
#### Post date: [May 10, 2017, 4:41pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/5 "2017-05-10T16:41:02Z")
post your gamemanger code and please use code tags - [Using code tags properly - Unity Engine - Unity Discussions](https://forum.unity3d.com/threads/using-code-tags-properly.143875/)
---
### Author:  [@johne5](https://discussions.unity.com/u/johne5)
#### Post date: [May 10, 2017, 4:48pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/6 "2017-05-10T16:48:04Z")
we need more code.
what is nextLevel? a string?
SceneManager.LoadScene(nextLevel);
---
### Author:  [@StarManta](https://discussions.unity.com/u/StarManta)
#### Post date: [May 10, 2017, 5:15pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/7 "2017-05-10T17:15:39Z")
> [@haydenbrown39](#):
>
> This is line 19
>
> gameManager.WinLevel();
That means gameManager is null. Where do you set the value of gameManager? Post that code.
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 10, 2017, 6:09pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/8 "2017-05-10T18:09:06Z")
Ok. I’ll get the whole GameManager code later
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 10, 2017, 6:37pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/9 "2017-05-10T18:37:04Z")
GameManager script.
using UnityEngine;
using UnityEngine.SceneManagement;
using System.Collections;
public class GameManager : MonoBehaviour {
bool gameHasEnded = false;
public float restartDelay = 1f;
public GameObject completeLevelUI;
public GameManager gameManager;
public string nextLevel = “Level02”;
public int levelToUnlock = 2;
public float completeDelay = 1f;
public void CompleteLevel()
{
completeLevelUI.SetActive(true);
gameManager.WinLevel();
}
public void EndGame ()
{
if (gameHasEnded == false)
{
gameHasEnded = true;
Debug.Log(“GAME OVER”);
Restart();
}
}
void Restart()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().name);
}
public void WinLevel()
{
Debug.Log(“LEVEL WON”);
PlayerPrefs.SetInt(“levelReached”, levelToUnlock);
SceneManager.LoadScene(nextLevel);
}
}
---
### Author:  [@WarmedxMints\_1](https://discussions.unity.com/u/WarmedxMints_1)
#### Post date: [May 10, 2017, 7:04pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/10 "2017-05-10T19:04:18Z")
You don’t need this`public GameManager gameManager;`unless you want to make a static instance.
You can also directly call WinLevel
```csharp
gameManager.WinLevel()
//Should be
WinLevel();
```
---
### Author:  [@johne5](https://discussions.unity.com/u/johne5)
#### Post date: [May 10, 2017, 9:40pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/11 "2017-05-10T21:40:05Z")
I think WarmedxMints is correct.
```csharp
using UnityEngine;
using UnityEngine.SceneManagement;
using System.Collections;
public class GameManager : MonoBehaviour {
bool gameHasEnded = false;
public float restartDelay = 1f;
public GameObject completeLevelUI;
public GameManager gameManager; //not needed. this is it's self
public string nextLevel = "Level02";
public int levelToUnlock = 2;
public float completeDelay = 1f;
public void CompleteLevel()
{
completeLevelUI.SetActive(true);
WinLevel();
}
public void EndGame ()
{
if (gameHasEnded == false)
{
gameHasEnded = true;
Debug.Log("GAME OVER");
Restart();
}
}
void Restart()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().name);
}
public void WinLevel()
{
Debug.Log("LEVEL WON");
PlayerPrefs.SetInt("levelReached", levelToUnlock);
SceneManager.LoadScene(nextLevel);
}
}
```
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 11, 2017, 7:32am UTC](https://discussions.unity.com/t/help-with-level-selector/664139/12 "2017-05-11T07:32:18Z")
Ok. Thanks. I’ll try this later
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 11, 2017, 2:41pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/13 "2017-05-11T14:41:44Z")
Right. That stopped the error, but now when I play the game, it stays on one level.
```auto
using UnityEngine;
using UnityEngine.SceneManagement;
using System.Collections;
public class GameManager : MonoBehaviour {
bool gameHasEnded = false;
public float restartDelay = 1f;
public GameObject completeLevelUI;
public string nextLevel = "Level02";
public int levelToUnlock = 2;
public float completeDelay = 1f;
public void CompleteLevel()
{
completeLevelUI.SetActive(true);
WinLevel();
}
public void EndGame ()
{
if (gameHasEnded == false)
{
gameHasEnded = true;
Debug.Log("GAME OVER");
Restart();
}
}
void Restart()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().name);
}
public void WinLevel()
{
Debug.Log("LEVEL WON");
PlayerPrefs.SetInt("levelReached", levelToUnlock);
SceneManager.LoadScene(nextLevel);
}
}
```
---
### Author:  [@WarmedxMints\_1](https://discussions.unity.com/u/WarmedxMints_1)
#### Post date: [May 11, 2017, 2:44pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/14 "2017-05-11T14:44:58Z")
Is Level02 included in your build?
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 11, 2017, 4:07pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/15 "2017-05-11T16:07:47Z")
As in, is it in the project folder? Yes
---
### Author:  [@methos5k](https://discussions.unity.com/u/methos5k)
#### Post date: [May 11, 2017, 4:08pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/16 "2017-05-11T16:08:49Z")
I think he meant in the project build settings page
---
### Author:  [@johne5](https://discussions.unity.com/u/johne5)
#### Post date: [May 11, 2017, 4:58pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/17 "2017-05-11T16:58:03Z")
it needs to be in the project build settings, if it is’t added then unity should have given an error when you tried to load it.
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 11, 2017, 4:59pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/18 "2017-05-11T16:59:22Z")
I’m sure that all the levels are in the build settings but I’ll check later. And I agree with johne5.
---
### Author:  [@methos5k](https://discussions.unity.com/u/methos5k)
#### Post date: [May 11, 2017, 5:08pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/19 "2017-05-11T17:08:39Z")
Is your situation like this: You play level 1, unlock level 2 and then it reloads level 1?
---
### Author:  [@haydenbrown39](https://discussions.unity.com/u/haydenbrown39)
#### Post date: [May 11, 2017, 8:42pm UTC](https://discussions.unity.com/t/help-with-level-selector/664139/20 "2017-05-11T20:42:01Z")
> [@methos5k](#):
>
> Is your situation like this: You play level 1, unlock level 2 and then it reloads level 1?
No, not exactly. My situation is that when I play level 1 it unlocks two, then when I win level 2 it goes back to the start of level 2.
[Next page](https://discussions.unity.com/t/help-with-level-selector/664139.md?page=2)