joomla module, "module xml data not available"

Hello i wanted to try make a joomla module. As im new to joomla, i tried to make a "hello program" first to see if it works, before i try to make a more complex one that i want.After i Installed it , joomla said it was successful , but when i try to run it , i get the "module xml data not available" error. I kinda tried everything i found to google for 2 hours now but still cant fix it. Is something i did wrong in the code ?

test.php

<?php
defined('__JEXEC') or die('error');
echo "test test test";
?>

mod_MEGAMENU.xml

<?xml version="1.0" encoding="utf-8"?>
<extension
    type="module"
    version="2.5.20"
    client="site"
    method="upgrade">
    <name>mod_megamenu</name>
    <author>Joomla test Project</author>
    <creationDate>November 2014</creationDate>
    <copyright>Copyright (C) 2013-14 noone. All rights reserved.</copyright>
    <license>GNU General Public License version 2 or later; see LICENSE.txt</license>
    <authorEmail>test@test.org</authorEmail>
    <authorUrl>http://ift.tt/1x6lPge;
    <version>2.5.20</version>
    <description>MOD_megamenu</description>
    <files>
        <filename>mod_MEGAMENU.xml</filename>
        <filename module="mod_megamenu">test.php</filename>
        <filename>index.html</filename>   
        <filename>credentials.php</filename> 
        <filename>connect.php</filename>        
    </files>
    <config>
    </config>

</extension>