structs-报错01-Document is invalid: no grammar found

一时手易做图，把structs-config.xml文件中的一段话删了，结果老是报错。
报错内容：Document is invalid: no grammar found
[html]
<?xml version="1.0" encoding="UTF-8"?>
<strong><span style="color:#ff0000;"><!DOCTYPE struts-config PUBLIC
       "-//Apache Software Foundation//DTD Tiles Configuration 1.3//EN"
       "http://jakarta.apache.org/struts/dtds/struts-config_1_3.dtd"></span></strong>
<struts-config>
    <form-beans>
        <form-bean name="helloForm" type="com.mars.demo01.structs01.form.HelloForm" />
    </form-beans>
    
    <global-exceptions />
    <global-forwards />
    <action-mappings>
        <action attribute="helloForm" input="/demo01/demo01_hello.jsp"
            name="helloForm" path="/demo01/demo01_hello" scope="request"
            type="com.mars.demo01.structs01.action.HelloAction" cancellable="true">
            <forward name="show" path="/demo01/demo01_hello.jsp"></forward>
        </action> www.zzzyk.com

    </action-mappings>
    
    <message-resources parameter="com.mars.demo01.structs01.ApplicationResources" />
</struts-config>
然后恢复原样，结果又好了，所以这句话是不能删的。在网上查了查，发现这是一个定义格式的东东。怎么弄的这么麻烦。

补充：Web开发 , Jsp ,