error typeerror: cannot read property 'y' of undefined about highcharts-ng HOT 2 CLOSED

            Tick.prototype.moveLabel = function (str, labelOptions) {
                var tick = this, label = tick.label, moved = false, xAxis = tick.axis, chart = xAxis.chart, labelPos, reversed = xAxis.reversed, inverted = chart.inverted, xPos, yPos;
                if (label && label.textStr === str) {
                    tick.movedLabel = label;
                    moved = true;
                    delete tick.label;
                }
                else { // Find a label with the same string
                    objectEach(xAxis.ticks, function (currentTick) {
                        if (!moved &&
                            !currentTick.isNew &&
                            currentTick !== tick &&
                            currentTick.label &&
                            currentTick.label.textStr === str) {
                            tick.movedLabel = currentTick.label;
                            moved = true;
                            currentTick.labelPos = tick.movedLabel.xy;
                            delete currentTick.label;
                        }
                    });
                }
                // Create new label if the actual one is moved
                // if (!moved && (tick.labelPos || label)) {
                if (!moved && (tick.labelPos || _.get(label,'xy',false))) {
                        labelPos = tick.labelPos || label.xy;
                    xPos = inverted ?
                        labelPos.x : (reversed ? 0 : xAxis.width + xAxis.left);
                    yPos = inverted ?
                        (reversed ? (xAxis.width + xAxis.left) : 0) : labelPos.y;
                    tick.movedLabel = tick.createLabel({ x: xPos, y: yPos }, str, labelOptions);
                    if (tick.movedLabel) {
                        tick.movedLabel.attr({ opacity: 0 });
                    }
                }
            };