Chart not rendered properly - php

Question

I have a small table
and want to create a TYPE_DONUTCHART with the PHPExcel library. I took the example code from the Examples/33chartcreate-pie.php file and adapted it accordingly:
$dataseriesLabels2 = array(
//new PHPExcel_Chart_DataSeriesValues('String', 'Summen!$A$1', NULL, 1),
);
$xAxisTickValues2 = array(
new PHPExcel_Chart_DataSeriesValues('String', 'Summen!$B$1:$C$1', NULL, 2),
);
$dataSeriesValues2 = array(
new PHPExcel_Chart_DataSeriesValues('Number', 'Summen!$B$2:$C$2', NULL, 2),
);
The file is served by the script, but when I try to open it, an error message occurs:
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.
When I click Yes and activate editing on the document, I get the following message like this:
Excel has finished the check and repair of your file. Some parts of this file have been repaired or discarded.
Removed part: Part /xl/drawings/drawing4.xml. (drawing form)
What's wrong in my code? What do I have to modify?
Notes:
As you can see, I'm using another dataset than in the example. There's only data in the range A1:C2 (see screenshot above).
The worksheets name is Summen, I double checked, that the problem is not a typo of the sheet.
It's been asked in the comments, I have already tried removing the comment from the dataseriesLabels2 entry.

Answer 1

My example
$objPHPExcel = new PHPExcel();
$objWorksheet = $objPHPExcel->getActiveSheet();
$objWorksheet->fromArray(
array(
array('Whatever', 'Cat1', 'Cat2'),
array(77, 247, 128),
)
);
$objWorksheet->setTitle('Summen');
$dataSeriesLabels1 = array(
// new PHPExcel_Chart_DataSeriesValues('String', 'Summen!$A$1', NULL, 1),
);
$xAxisTickValues1 = array(
new PHPExcel_Chart_DataSeriesValues('String', 'Summen!$B$1:$C$1', NULL, 2),
);
$dataSeriesValues1 = array(
new PHPExcel_Chart_DataSeriesValues('Number', 'Summen!$B$2:$C$2', NULL, 2),
);
$series1 = new PHPExcel_Chart_DataSeries(
PHPExcel_Chart_DataSeries::TYPE_DONUTCHART, // plotType
NULL, // plotGrouping
range(0, count($dataSeriesValues1)-1), // plotOrder
$dataSeriesLabels1, // plotLabel
$xAxisTickValues1, // plotCategory
$dataSeriesValues1 // plotValues
);
$layout1 = new PHPExcel_Chart_Layout();
$layout1->setShowVal(TRUE);
$layout1->setShowPercent(TRUE);
$plotArea1 = new PHPExcel_Chart_PlotArea($layout1, array($series1));
$legend1 = new PHPExcel_Chart_Legend(PHPExcel_Chart_Legend::POSITION_RIGHT, NULL, false);
$title1 = new PHPExcel_Chart_Title('Test Pie Chart');
$chart1 = new PHPExcel_Chart(
'chart1', // name
$title1, // title
$legend1, // legend
$plotArea1, // plotArea
true, // plotVisibleOnly
0, // displayBlanksAs
NULL, // xAxisLabel
NULL // yAxisLabel - Pie charts don't have a Y-Axis
);
// Set the position where the chart should appear in the worksheet
$chart1->setTopLeftPosition('A7');
$chart1->setBottomRightPosition('H20');
// Add the chart to the worksheet
$objWorksheet->addChart($chart1);
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
$objWriter->setIncludeCharts(TRUE);
$objWriter->save(str_replace('.php', '.xlsx', __FILE__));
generates correctly without any errors