Warning in PHP 7.4

I have the latest version of Matomo installed on Debian Buster and PHP 7.4 and Apache

When I go to the configuration page, I see a warning at the top,

</> /var/www/html/piwik/core/DataTable/Filter/ColumnDelete.php(164): Deprecated - array_key_exists(): Using array_key_exists() on objects is deprecated. Use isset() or property_exists() instead - Matomo 3.13.0 - Please report this message in the Matomo forums: https://forum.matomo.org (please do a search first as it might have been reported already) (Module: VisitsSummary, Action: getEvolutionGraph, In CLI mode: false)</>

I suspect it’s something to do with PHP 7.4


This is one of the few 7.4 bugs that slipped through in Matomo 3.13.

It is fixed with