Adding more than 26 columns in a chart data worksheet is resulting in corrupted data. There is no error message when you open the file, but the chart data will not load. If you extract the pptx file and browse to ppt\embeddings and try to open the xlsx file independently it reports unreadable content.
Code to reproduce:
public static void main(String[] args) {
PresentationEx pres = new PresentationEx();
SlideEx slide = pres.getSlides().get_Item(0);
ChartEx c = slide.getShapes().addChart(
ChartTypeEx.ClusteredColumn, 0, 0, 500, 500);
ChartDataEx cd = c.getChartData();
cd.getSeries().clear();
cd.getCategories().clear();
ChartDataCellFactory data =
cd.getChartDataCellFactory();
data.clear(0);
ChartSeriesEx series = cd.getSeries().get_Item(
cd.getSeries().add(data.getCell(
0, 1, 0, "Series 1"), c.getType()));
for(int i = 0; i <=25; i++) {
cd.getCategories().add(data.getCell(0, 0, i+1, "Category "+i));
series.getValues().add(data.getCell(0, 1, i+1, i));
}
pres.write("out.pptx");
}