added notification when opening locked scenes

Assets/Editor/NotifyForLockedFiles.cs

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
+using UnityEngine.SceneManagement;
+using UnityEditor;
+using UnityEditor.SceneManagement;
 using System.IO;
 
+[InitializeOnLoad]
 public class NotifyForLockedFiles : UnityEditor.AssetModificationProcessor
+{
+	static NotifyForLockedFiles()
+	{
+		EditorSceneManager.activeSceneChangedInEditMode += CheckActivatedScene;
+		if (EditorSceneManager.GetActiveScene() != null)
+		{
+			CheckActivatedScene(EditorSceneManager.GetActiveScene(), EditorSceneManager.GetActiveScene());
+		}
+	}
+
+
+    public static string[] OnWillSaveAssets(string[] paths)
     {
-        public static string[] OnWillSaveAssets(string[] paths)
+        List<string> pathsToSave = new List<string>();
+
+        for (int i = 0; i < paths.Length; ++i)
         {
-            List<string> pathsToSave = new List<string>();
- 
-            for (int i = 0; i < paths.Length; ++i)
-            {
-                FileInfo info = new FileInfo(paths[i]);
-                if (info.IsReadOnly)
-                    UnityEditor.EditorUtility.DisplayDialog("Can not save.",
-                    "Sorry, but " + paths[i] + " is Read-Only! Please Save as another name.",
-                    "Ok");
-                else
-                    pathsToSave.Add(paths[i]);
-            }
- 
-            return pathsToSave.ToArray();
+            FileInfo info = new FileInfo(paths[i]);
+            if (info.IsReadOnly)
+                UnityEditor.EditorUtility.DisplayDialog("Konnte nicht speichern",
+                "Die Scene " + paths[i] + " ist Read-Only. Sie konnte nicht gespeichert werden. Sie kann aber unter anderem Namen gespeichert werden.",
+                "Ok");
+            else
+                pathsToSave.Add(paths[i]);
         }
+
+        return pathsToSave.ToArray();
+    }
+
+    public static void CheckActivatedScene(Scene oldScene, Scene newScene)
+    {
+    	Debug.Log(newScene.path);
+    	FileInfo info = new FileInfo(newScene.path);
+    	if (info.IsReadOnly)
+    	{
+    		UnityEditor.EditorUtility.DisplayDialog("Read-Only", "Die Scene " + newScene.path + " ist Read-Only. Sie wird nicht gespeichert werden können.", "Ok");
+    	}
     }
+}
  
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