# What is unity problem?
**URL:** https://discussions.unity.com/t/what-is-unity-problem/917172
**Category:** Editor Extensions
**Tags:** Scripting, Performance, Question
**Created:** [May 7, 2023, 1:11pm UTC](https://discussions.unity.com/t/what-is-unity-problem/917172 "2023-05-07T13:11:59Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@LazyGhost15](https://discussions.unity.com/u/LazyGhost15)
#### Post date: [May 7, 2023, 1:11pm UTC](https://discussions.unity.com/t/what-is-unity-problem/917172/1 "2023-05-07T13:11:59Z")
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.PropertyHandler.IsArrayReorderable (UnityEditor.SerializedProperty property) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
UnityEditor.PropertyHandler.UseReorderabelListControl (UnityEditor.SerializedProperty property) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
UnityEditor.PropertyHandler.GetHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
UnityEditor.EditorGUI.GetPropertyHeightInternal (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
UnityEditor.EditorGUI.GetPropertyHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
UnityEditor.Editor.CanBeExpandedViaAFoldoutWithoutUpdate () (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
UnityEditor.UIElements.EditorElement.UpdateInspectorVisibility () (at \<0fdaf67e8e744beea25e77915c19f81b\>:0)
UnityEditor.UIElements.EditorElement.Init () (at \<0fdaf67e8e744beea25e77915c19f81b\>:0)
UnityEditor.UIElements.EditorElement…ctor (System.Int32 editorIndex, UnityEditor.IPropertyView iw, System.Boolean isCulled) (at \<0fdaf67e8e744beea25e77915c19f81b\>:0)
UnityEditor.EditorUIServiceImpl.CreateEditorElement (System.Int32 editorIndex, UnityEditor.IPropertyView iw, System.String title) (at \<80d791e9b1714d8c9c1d90aef484ea86\>:0)
UnityEditor.PropertyEditor.DrawEditors (UnityEditor.Editor[ ] editors) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
UnityEditor.PropertyEditor.RebuildContentsContainers () (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
UnityEditor.InspectorWindow.RedrawFromNative () (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
I made 2D tilemap then this started popping
---
### Author:  [@karderos](https://discussions.unity.com/u/karderos)
#### Post date: [May 7, 2023, 1:41pm UTC](https://discussions.unity.com/t/what-is-unity-problem/917172/2 "2023-05-07T13:41:45Z")
> [@LazyGhost15](#):
>
> NullReferenceException: Object reference not set to an instance of an object
> UnityEditor.PropertyHandler.IsArrayReorderable (UnityEditor.SerializedProperty property) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
> UnityEditor.PropertyHandler.UseReorderabelListControl (UnityEditor.SerializedProperty property) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
> UnityEditor.PropertyHandler.GetHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
> UnityEditor.EditorGUI.GetPropertyHeightInternal (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
> UnityEditor.EditorGUI.GetPropertyHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
> UnityEditor.Editor.CanBeExpandedViaAFoldoutWithoutUpdate () (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
> UnityEditor.UIElements.EditorElement.UpdateInspectorVisibility () (at \<0fdaf67e8e744beea25e77915c19f81b\>:0)
> UnityEditor.UIElements.EditorElement.Init () (at \<0fdaf67e8e744beea25e77915c19f81b\>:0)
> UnityEditor.UIElements.EditorElement…ctor (System.Int32 editorIndex, UnityEditor.IPropertyView iw, System.Boolean isCulled) (at \<0fdaf67e8e744beea25e77915c19f81b\>:0)
> UnityEditor.EditorUIServiceImpl.CreateEditorElement (System.Int32 editorIndex, UnityEditor.IPropertyView iw, System.String title) (at \<80d791e9b1714d8c9c1d90aef484ea86\>:0)
> UnityEditor.PropertyEditor.DrawEditors (UnityEditor.Editor[ ] editors) (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
> UnityEditor.PropertyEditor.RebuildContentsContainers () (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
> UnityEditor.InspectorWindow.RedrawFromNative () (at \<0c3742f371b24679bcaa6fcc508d0cca\>:0)
>
> I made 2D tilemap then this started popping
Object reference not set to an instance of an object
---
### Author:  [@LazyGhost15](https://discussions.unity.com/u/LazyGhost15)
#### Post date: [May 7, 2023, 1:59pm UTC](https://discussions.unity.com/t/what-is-unity-problem/917172/3 "2023-05-07T13:59:44Z")
> [@karderos](#):
>
> Object reference not set to an instance of an object
I understood that but unity didnt say in which script or object his talking about. even if I clicked the Error
---
### Author:  [@Kurt-Dekker](https://discussions.unity.com/u/Kurt-Dekker)
#### Post date: [May 7, 2023, 2:06pm UTC](https://discussions.unity.com/t/what-is-unity-problem/917172/4 "2023-05-07T14:06:57Z")
How to fix a NullReferenceException error
[https://forum.unity.com/threads/how-to-fix-a-nullreferenceexception-error.1230297/](https://forum.unity.com/threads/how-to-fix-a-nullreferenceexception-error.1230297/)
Three steps to success:
- Identify what is null **← any other action taken before this step is WASTED TIME**
- Identify why it is null
- Fix that