title: Error when trying to use a .docx file for the Merge
body: <p>Working Visual Studio, using Merge Refactor to file in a online form and merge the data into a word document, when using a .doc file, everything works fine, but when I try to use a .docx file, I get the following error, any assistance would be great!</p>
  
  <p>Cannot find target of relationship '<a href="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" rel="nofollow noreferrer">http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument</a>'
  Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. </p>
  
  <blockquote>
    <p>Exception Details: System.InvalidOperationException: Cannot find
    target of relationship
    '<a href="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" rel="nofollow noreferrer">http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument</a>'</p>
    
    <p>Source Error:</p>
    
    <p>Line 85:          var selectedDocumentPath =
    DocumentDDL.Items[DocumentDDL.SelectedIndex].Value;</p>
    
    <p>Line 86:          var ext =
    System.IO.Path.GetExtension(selectedDocumentPath);</p>
    
    <p>Line 87:             Document doc = new
    Document(selectedDocumentPath);</p>
    
    <p>Line 88:            </p>
    
    <p>Line 89:          var mergeData = ConstructMergeData();</p>
  </blockquote>