Unity Find missing references

FindMissingEditor.cs

using UnityEngine;
using UnityEditor;

public class FindMissingEditor : EditorWindow
{
	[MenuItem(itemName: "Menu/Find Missing References")]
	public static void Open()
	{
		EditorWindow.GetWindow<FindMissingEditor>("Find Missing References").Show();
	}

	private void OnGUI()
	{
		if (GUILayout.Button("Missing in Hierarchy"))
		{
			int sceneCount = UnityEngine.SceneManagement.SceneManager.sceneCount;
			for (int i = 0; i < sceneCount; ++i)
			{
				var scene = UnityEngine.SceneManagement.SceneManager.GetSceneAt(i);
				var roots = scene.GetRootGameObjects();
				foreach (var go in roots)
				{
					FindMissing(go);
				}
			}
		}
		if (GUILayout.Button("Missing in Prefabs"))
		{
			string[] guids = AssetDatabase.FindAssets("t:prefab");
			for (int i = 0; i < guids.Length; ++i)
			{
				var path = AssetDatabase.GUIDToAssetPath(guids[i]);
				var go = AssetDatabase.LoadAssetAtPath<GameObject>(path);
				if (go != null)
				{
					FindMissing(go);
				}
			}
		}
	}

	private void FindMissing(GameObject go)
	{
		var transforms = go.GetComponentsInChildren<Transform>();
		foreach (var t in transforms)
		{
			int missingScripts = GameObjectUtility.GetMonoBehavioursWithMissingScriptCount(t.gameObject);
			if (missingScripts > 0)
			{
				Debug.LogError($"{t.gameObject.name} has missing script(s)", t.gameObject);
			}

			var components = t.gameObject.GetComponents<MonoBehaviour>();
			foreach (var c in components)
			{
				if (c == null) { continue; }
				var serializedObject = new SerializedObject(c);
				var it = serializedObject.GetIterator();
				while (it.NextVisible(true))
				{
					if (it.propertyType == SerializedPropertyType.ObjectReference)
					{
						if (it.objectReferenceValue == null && it.objectReferenceInstanceIDValue != 0)
						{
							Debug.LogError($"{t.gameObject.name}.{c.GetType().Name}.{it.displayName} has missing reference", c);
						}
					}
				}
			}
		}
	}
}