Highcharts already defined in the page

This error happens if the Highcharts namespace already exists when loading Highcharts or Highstock.

This is caused by including Highcharts or Highstock more than once.

Keep in mind that the Highcharts.Chart constructor and all features of Highcharts are included in Highstock, so if using the Chart and StockChart constructors in combination, only the highstock.js file is required.