C# Nhibernate无法编译映射文件

我的Customer.cfg.xml文件是：

<?xml version="1.0" encoding="utf-8" ?>
 <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true" 
  assembly="OnlineShop" 
   namespace="OnlineShop">
   <class name="Customer" table="Customer" dynamic-update="true" >
    <cache usage="read-write"/>
    <id name="CustomerID" column="CustomerID" type="long">
        <generator class="native" />
    </id>

    <property name="Name"  />
    <property name="Fname" />
    <property name="Phone" />
</class>
</hibernate-mapping>

但是我得到一个错误，说不能编译Customer.cfg.Xml文件

这是我的解决方案屏幕截图

---

我认为这是因为文件末尾缺少关闭选项卡

 public class Customer
{
    public virtual long CustomerID { get; set; }
    public virtual string Name { get; set; }
    public virtual string Fname { get; set; }
    public virtual string Phone { get; set; }
}