title: xlsx and xlsm files return badzipfile: file is not a zip file
body: <p>I'm trying to open both an xlsx file and an xlsm file both give me the same error</p>
  
  <blockquote>
    <p>badzipfile: file is not a zip file</p>
  </blockquote>
  
  <p>here is what I'm typing:</p>
  
  <pre><code>import openpyxl
  wb=openpyxl.load_workbook('c:\\users\\me\\documents\\filename.xlsm', keep_vba=True)
  wb2=openpyxl.load_workbook('c:\\users\\me\\documents\\filename2.xlsx')
  </code></pre>
  
  <p>both <code>load_workbook</code> commands result in the same error. They both exist at that location. why am I getting this error?</p>