Uncaught TypeError: l.renderElement is not a function

Question

I have a shared tooltip for my graph:

            $scope.kissaChart.setOptions({
                renderAs: 'canvas',
                drag: onDrag,
                dragEnd: onDragEnd,
                zoom: onZoom,
                tooltip: {
                    visible: true,
                    format: "{0:n2}",
                    shared: true,
                    background: '#ADD8E6',
                    sharedTemplate: createTemplate
                }
            });

Here is my template generator :

function createTemplate (val1) {
    var template = "";
    if (val1 && val1.points && val1.points && val1.points.length > 0) {
        template += "<div>";

        // construct Date
        template += "Date: ";
        template += ((val1.points[0].dataItem.date) ? val1.points[0].dataItem.date : "");
        template += " " + ((val1.points[0].dataItem.actualTime) ? val1.points[0].dataItem.actualTime : "");
    }
    return template;
}

When I try to do mouseover a data on my series, I am shown :

Uncaught TypeError: l.renderElement is not a function

What could have been the reason?