title: ApexChart TypeError: "c is undefined" when update chart
body: <p>I started using ApexChart and it worked fine to create the chart, but it's returning a error "c is undefined" when I try to update the chart.</p>
  
  <p>How I create the chart is below. dates is an array with some dates and values an array with numbers</p>
  
  <pre><code>var options = {
      chart: {
          height: 350,
          type: 'area',
          zoom: {
              enabled: false
          }
      },
      dataLabels: {
          enabled: false
      },
      stroke: {
          curve: 'straight'
      },
      series: [{
          name: "Sales",
          data: values
      }],
      title: {
          text: 'Number os sales',
          align: 'left'
      },
      labels: dates,
      xaxis: {
          type: 'datetime'
      },
      yaxis: {
          opposite: true
      },
      legend: {
          horizontalAlign: 'left'
      }
  }
  var chart = new ApexCharts(
      document.querySelector("#salesChart"),
      options
  )
  if (document.getElementById('salesChart')) {
      chart.render();
  }
  </code></pre>
  
  <p>Then, I try to update the chart by:</p>
  
  <pre><code>// Update label
  ApexCharts.exec('salesChart', 'updateOptions', {
      xaxis: {
          labels: dates
      }
  }, false, true)
  // Update values
  ApexCharts.exec('salesChart', 'updateSeries', [{
      data: values
  }], true);
  </code></pre>
  
  <p>The update above is called when I set a new values for the arrays dates and values.
  It's returning the error:</p>
  
  <pre><code>TypeError: "c is undefined"
      getChartByID http://myserver.com/assets/js/vendors/charts/apex-charts.js:27013
      exec http://myserver.com/assets/js/vendors/charts/apex-charts.js:26952
  </code></pre>