Spring.Context.Support.ContextRegistry”的类型初始值设定项引发异常

最近刚学srping.net 做了一个例子，运行时总是报如题的错误，请问是怎么回事？using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Spring.Context;
using Spring.Context.Support;
namespace SpringNhiberateStart
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }        private void btnGetObject_Click(object sender, EventArgs e)
        {
            try
            {
                //拿到容器上下文
                IApplicationContext ctx = ContextRegistry.GetContext();
                //通过容器获取 对象实例
                var order = (Order)ctx.GetObject("order");
                if (order == null)
                {
                    MessageBox.Show("Error");
                }
                else
                {
                    order.Id = 3;
                    order.Content = "shit";
                    order.ShowOrder();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }        }
    }
}<?xml version="1.0"?>
<configuration>
  <configSections>
    <sectionGroup name="spring">
      <section name="context" type="Spring.Context.Support.ContextHandler, Spring.Core"/>
      <section name="objects" type="Spring.Context.Support.DefaultSectionHandler, Spring.Core"/>
    </sectionGroup>
  </configSections>
  <spring>
    <context>
      <resource uri="config://spring/objects"/>
      <resource uri="assembly://SpringNhiberateStart/SpringNhiberateStart/SpringObjects.xml"/>
    </context>
    
    <!--容器下的所有的实例的节点都放在此配置下-->
    <objects xmlns="http://www.springframework.net">
      <description>An  example that demonstrates simple IoC features.</description>
      <!--type：第一个是类型的全名 ，类型所在的程序集-->
      <object name="order" type="SpringNhiberateStart.Order,SpringNhiberateStart">
      </object>
    </objects>
  </spring>
</configuration>