title: Open XML: We found a problem with some content in 'myfile.xlsx'
body: <p>I am creating an Excel file using the Open XML SDK.</p>
  
  <pre><code>Worksheet newWs = new Worksheet()
  {
      MCAttributes = new MarkupCompatibilityAttributes() { Ignorable = "x14ac" }
  };
  </code></pre>
  
  <p>When I add a <code>SheetViews</code> instance as follows,</p>
  
  <pre><code>SheetViews sheetViews = new SheetViews();
  SheetView sheetView = new SheetView();
  Selection selection = new Selection() { ActiveCell = "B1" };
  sheetView.Append(selection);
  sheetViews.Append(sheetView);
  newWs.Append(sheetViews);
  </code></pre>
  
  <p>I get an error as shown below (and also <code>ActiveCell</code> is not working):</p>
  
  <blockquote>
    <p>We found a problem with some content in 'myfile.xlsx'. Do you want us
    to try to recover as much as we can? If you trust the source of this
    workbook, click Yes.</p>
  </blockquote>