Hello,
i am using this external library: https://blacklabel.github.io/grouped_categories/ for more dimensional categories.
Sadly i got an error when i updated my highcharts version to 11 as you can see here: http://jsfiddle.net/BlackLabel/059gfznh/
Here is a screenshot of the errormessage: https://ibb.co/PrS2WFd
Is there any way to fix this from your side or is there a way that i can use specific attributes to avoid this error?
Waiting for your reply,
Best regards!