Maximum call stack size exceeded error - after grouping two tables

Mlodey

I'm using two tables in one view as below:

<table id="dt_WeeksPlanTable" class="display table table-bordered dataTable no-footer" cellspacing="0">
    <thead>
        <tr>
            <th>Stream</th>
            <th>Team</th>
            <th>Project</th>
            <th>Activity</th>

            <th>W+1</th>
            <th>W+2</th>
            <th>W+3</th>
            <th>W+4</th>
            <th>W+5</th>
            <th>W+6</th>
            
        </tr>
    </thead>

</table>


<table id="dt_SummaryReportTable" class="display table table-bordered dataTable no-footer" cellspacing="0">
    <thead>
        <tr>
            <th rowspan="2">Stream</th>
            <th rowspan="2">Team</th>

            <th colspan="2">W+1</th>
            <th colspan="2">W+2</th>
            <th colspan="2">W+3</th>
            <th colspan="2">W+4</th>
            <th colspan="2">W+5</th>
            <th colspan="2">W+6</th>

        </tr>
        <tr>
            <th>Hours</th>
            <th>Comment</th>

            <th>Hours</th>
            <th>Comment</th>

            <th>Hours</th>
            <th>Comment</th>

            <th>Hours</th>
            <th>Comment</th>

            <th>Hours</th>
            <th>Comment</th>

            <th>Hours</th>
            <th>Comment</th>
        </tr>
    </thead>
</table>

var $reportTable =
                $('#dt_WeeksPlanTable').DataTable({

                    "sDom": '<"top"i>rt<"bottom"flBp><"clear">',
                    "buttons": ['excelFlash'],

                    "bFilter": false,

                    "aaSorting": [],
                    //"order": [[0, "asc"], [1, "asc"]],
                    "columns": [

                        { "data": "StreamName", "name": "weeksStream", "width": "5%" },
                        { "data": "TeamName", "width": "10%" },
                        { "data": "ProjectName", "width": "7%" },
                        { "data": "ActivityName", "width": "18%" },

                        { "data": "W1", "width": "10%" },
                        { "data": "W2", "width": "10%" },
                        { "data": "W3", "width": "10%" },

                        { "data": "W4", "width": "6%" },
                        { "data": "W5", "width": "6%" },
                        { "data": "W6", "width": "6%" }

                    ],

                    rowsGroup: [
                        'weeksStream:name'
                    ],
                });


            var $summaryReportTable =
                $('#dt_SummaryReportTable').DataTable({

                    "sDom": '<"top"i>rt<"bottom"flBp><"clear">',
                    "buttons": ['excelFlash'],

                    "bFilter": false,

                    "aaSorting": [],
                    "columns": [
                        { "data": "Stream", "name": "sumStream", "width": "5%" },
                        { "data": "TeamName", "width": "10%" },

                        { "data": "W1H", "width": "3%" },
                        { "data": "W1C", "width": "11%" },

                        { "data": "W2H", "width": "3%" },
                        { "data": "W2C", "width": "11%" },

                        { "data": "W3H", "width": "3%" },
                        { "data": "W3C", "width": "11%" },

                        { "data": "W4H", "width": "3%" },
                        { "data": "W4C", "width": "11%" },

                        { "data": "W5H", "width": "3%" },
                        { "data": "W5C", "width": "11%" },

                        { "data": "W6H", "width": "3%" },
                        { "data": "W6C", "width": "11%" }
                    ],

                    rowsGroup: [
                        'sumStream:name'
                    ]
                });

When page is loading I'm getting an error: Uncaught RangeError: Maximum call stack size exceeded.
The error is always when grouping is set on in both tables, but in other cases it loads as it should. In this step the data is not even loaded, I'm loading it after button click.

Is it a bug?