Unfortunately, he's right. He is trying the install version, however the zip file contains an incorrect .dnn file.

I suggest you try the source version or adapt the .dnn file in the Install zip file to look like this (not tested by me however) :

<dotnetnuke version="3.0" type="Module">
  <folders>
    <folder>
      <name>DNN_Documents</name>
      <friendlyname>Documents</friendlyname>
      <foldername>Documents</foldername>
      <modulename>DNN_Documents</modulename>
      <description>This module renders a list of documents, including links to browse or download the document. Documents includes an edit page, which allows authorized users to edit the information about the Documents (for example, a friendly title) stored in the SQL database.</description>
      <version>03.01.03</version>
      <businesscontrollerclass>DotNetNuke.Modules.Documents.DocumentController, DotNetNuke.Modules.Documents</businesscontrollerclass>
      <resourcefile></resourcefile>
      <modules>
        <module>
          <friendlyname>Documents</friendlyname>
          <cachetime>0</cachetime>
          <controls>
            <control>
              <src>DesktopModules/Documents/Document.ascx</src>
              <type>View</type>
              <helpurl>http://www.dotnetnuke.com/default.aspx?tabid=787</helpurl>
            </control>
            <control>
              <key>Edit</key>
              <title>Edit Documents</title>
              <src>DesktopModules/Documents/EditDocs.ascx</src>
              <type>Edit</type>
              <helpurl>http://www.dotnetnuke.com/default.aspx?tabid=787</helpurl>
            </control>
            <control>
              <key>Settings</key>
              <title>Documents Settings</title>
              <src>DesktopModules/Documents/EditDocumentsSettings.ascx</src>
              <type>Edit</type>
              <helpurl>http://www.dotnetnuke.com/default.aspx?tabid=787</helpurl>
            </control>
          </controls>
        </module>
      </modules>
      <files>
        <file>
          <name>DotNetNuke.Modules.Documents.dll</name>
        </file>
        <file>
          <name>DotNetNuke.Modules.Documents.SqlDataProvider.dll</name>
        </file>
        <file>
          <name>Document.ascx</name>
        </file>
        <file>
          <name>EditDocs.ascx</name>
        </file>
        <file>
          <name>EditDocumentsSettings.ascx</name>
        </file>
        <file>
          <name>module.css</name>
        </file>
        <file>
          <name>Release Notes - 03.01.02.txt</name>
        </file>
        <file>
          <path>App_LocalResources</path>
          <name>Document.ascx.resx</name>
        </file>
        <file>
          <path>App_LocalResources</path>
          <name>EditDocs.ascx.resx</name>
        </file>
        <file>
          <path>App_LocalResources</path>
          <name>EditDocumentsSettings.ascx.resx</name>
        </file>
        <file>
          <name>03.01.00.SqlDataProvider</name>
        </file>
        <file>
          <name>03.01.01.SqlDataProvider</name>
        </file>
        <file>
          <name>03.01.02.SqlDataProvider</name>
        </file>
        <file>
          <name>Uninstall.SqlDataProvider</name>
        </file>
      </files>
    </folder>
  </folders>
</dotnetnuke>