title: JasperReports xlsx export error - Unreadable content - why?
body: <p>receive an "Unreadable Content" error from Excel whenever the results of my crosstab report is > 702 columns (column ZZ).   When less than this number of columns - no error.  Is there a limit?  XLSX should handle 16,000+ columns.</p>
  
  <p>We are using JasperReports v4.0.1 and POI 3.6.  I have attempted and recreated this same issue using JasperReports v4.7 and POI 3.7.</p>
  
  <p>Any help or insight is appreciated.</p>
  
  <p>Export Code:</p>
  
  <pre><code>JRXlsxExporter xlsExporter = new JRXlsxExporter();
  
  File fileP = new File(_workdir + report_name + ".jrprint");
  JasperPrint jasperPrint = (JasperPrint)
  JRLoader.loadObject(fileP);
  
  xlsExporter.setParameter(JRXlsExporterParameter.IS_ONE_PAGE_PER_SHEET, Boolean.TRUE);
  xlsExporter.setParameter(JRXlsExporterParameter.IS_REMOVE_EMPTY_SPACE_BETWEEN_ROWS, Boolean.TRUE);
  xlsExporter.setParameter(JRXlsExporterParameter.IS_DETECT_CELL_TYPE, Boolean.TRUE);
  xlsExporter.setParameter(JRXlsExporterParameter.IS_WHITE_PAGE_BACKGROUND, Boolean.FALSE);
  xlsExporter.setParameter(JRXlsExporterParameter.IS_REMOVE_EMPTY_SPACE_BETWEEN_COLUMNS, Boolean.TRUE);
  xlsExporter.setParameter(JRXlsExporterParameter.IS_COLLAPSE_ROW_SPAN, Boolean.TRUE);
  
  xlsExporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
  xlsExporter.setParameter(JRExporterParameter.OUTPUT_FILE_NAME, _outputName);
  System.out.println("Exporting Excel Report to " + _outputName);
  xlsExporter.exportReport();
  System.out.println("Export Complete.");
  </code></pre>