Error when init a scriptableWizard

I am trying to create my own ScriptableWizard , I put my code at the folder Assets/Editor , the file name is the same with the class name. But when I open it using a menu item ,I got the error:

 Instance of MyScriptableWizard couldn't be created because there is no script with that name.
 UnityEditor.ScriptableWizard:DisplayWizard(String, Type)
 MyScriptableWizard:CreateWizard() (at Assets/Editor/MyScriptableWizard .cs:24)

Here is code:

 using UnityEngine;
 using UnityEditor;
 using System.Collections;
 
 // A Wizard class that generates it's fields from public properties
 public class MyScriptableWizard : ScriptableWizard
 {
     //---------------------------------
     // Reflection Fields
     //---------------------------------
  
     // An auto generated field
     public string myGeneratedField;
  
     //---------------------------------
     // Static Methods
     //---------------------------------
  
     // Create the wizard
     [MenuItem ("GameObject/Wizards/My Scriptable Wizard")]
     static void CreateWizard ()
     {
         MyScriptableWizard wizard = DisplayWizard<MyScriptableWizard>("My Scriptable Wizard", "Wizard Create", "Wizard Other Button");

     }
  
     //==================================
     // Messages
     //==================================
  
  
     // Called every frame when the wizard is visible.
     void OnDrawGizmos()
     {
  
     }
  
     // This is called when the user clicks on the Create button.
     void OnWizardCreate()
     {
  
     }
  
     // This is called when the wizard is opened or whenever the user 
     // changes something in the wizard.
     void OnWizardUpdate()
     {
  
     }
  
     // Allows you to provide an action when the user clicks on the 
     // other button.
     void onWizardOtherButton()
     {
     }
 }