Angular-Chart cannot read propery 'skip' of undefined

I have the following chart on angular-chart:

<canvas id="line" class="chart chart-line" chart-data="data"  chart-colors="colors"
        chart-series="series" chart-options="options">
</canvas>

With this options:

$scope.options = {
  type:'line',
  tooltips: {
    enabled: false
  },
  showTooltips: false,
  hover: {mode: null},
  scales: {
    xAxes: [{
      type:"time"
    }]
  }
};

Im updating the data via a websocket like this:

channel.on("create:entry", function (msg) {
  // Before updating the data, set the new time to the current time
  $log.log("received entry");
  $log.log(msg);
  // Refetch the data points
  $scope.data[0].push(
    {
      x: new Date(),
      y: msg.sonnar
    });
  vm.current = msg.sonnar;
  vm.logEntries.splice(0, 0, {time: moment(new Date()).format("MMMM Do YYYY, h:mm:ss a"), level: msg.sonnar});

});

The chart updates the right way for a couple of entries. But if I hover on the chart I get the error:

TypeError: Cannot read property 'skip' of undefined.

This is the function on Chart js where the app crashes:

/**
     * Helper function to traverse all of the visible elements in the chart
     * @param chart {chart} the chart
     * @param handler {Function} the callback to execute for each visible item
     */
    function parseVisibleItems(chart, handler) {
        var datasets = chart.data.datasets;
        var meta, i, j, ilen, jlen;

        for (i = 0, ilen = datasets.length; i < ilen; ++i) {
            if (!chart.isDatasetVisible(i)) {
                continue;
            }

            meta = chart.getDatasetMeta(i);
            for (j = 0, jlen = meta.data.length; j < jlen; ++j) {
                var element = meta.data[j];
                if (!element._view.skip) {
                    handler(element);
                }
            }
        }
    }

Can anyone help me solve the problem?