Hi,

The current version of Excel package has some chart open issue in Microsoft Office. We will fix that in the next release of KoolReport. Meanwhile you could try this fix to see if it works. Please open the file koolreport/excel/Chart.php and replace the following line:

        $chart = new PHPOfficeChart(
            $chartName, // name
            $title, // title
            $legend, // legend
            $plotArea, // plotArea
            true, // plotVisibleOnly
            0, // displayBlanksAs
            $xAxisLabel, // xAxisLabel
            $yAxisLabel,  // yAxisLabel
            $yaxis,
            $xaxis
        );

with these:

        $chart = new PHPOfficeChart(
            $chartName, // name
            $title, // title
            $legend, // legend
            $plotArea, // plotArea
            true, // plotVisibleOnly
            'gap', // displayBlanksAs
            $xAxisLabel, // xAxisLabel
            $yAxisLabel,  // yAxisLabel
            $yaxis,
            $xaxis
        );

Thanks!