Issue #3461759: TypeError: array_values(): Argument #1 ($array) must be of...

Issue #3461759: TypeError: array_values(): Argument #1 ($array) must be of type array, null given in array_values() - line 445 of ...Highcharts.php

modules/charts_highcharts/src/Plugin/chart/Library/Highcharts.php

@@ -442,7 +442,7 @@ class Highcharts extends ChartBase implements ContainerFactoryPluginInterface {
     }
 
     // Remove machine names from series. Highcharts series must be an array.
-    $series = array_values($chart_definition['series']);
+    $series = !empty($chart_definition['series']) ? array_values($chart_definition['series']) : [];
     unset($chart_definition['series']);
 
     // Trim out empty options (excluding "series" for efficiency).