title: recreate excel .xlsx file from unzipped xml folder
body: <p>I'm trying to convert a folder of xml that was created by unzipping an excel file back into an excel .xlsx. But I get the error</p>
  <blockquote>
  <p>The workbook cannot be opened or repaired by Microsoft Excel because it is corrupt</p>
  </blockquote>
  <p><strong>A minimal reproducible example to generate this error:</strong></p>
  <ol>
  <li>Create a new blank spreadsheet in Excel</li>
  <li>Enter &quot;test&quot; in cell A1</li>
  <li>Save as <code>test.xlsx</code></li>
  <li>Rename file to <code>test.zip</code></li>
  <li>Unzip <code>test.zip</code> as a folder named <code>test</code></li>
  <li>Compress <code>test</code> into <code>test_new.zip</code></li>
  <li>Rename <code>test_new.zip</code> as <code>test_new.xlsx</code></li>
  <li>Open <code>test_new.xlsx</code> with Excel</li>
  </ol>
  <p>For zipping and unzipping I have used 7zip, WinZip and PeaZip, all with the same result. What am I doing wrong, and how can I turn unzipped excel workbooks back into their original form?</p>