FATAL EXCEPTION: TypeError - array_key_exists(): Argument #2 ($array) must be of type array, ActivityList given<br/>#0 /var/www/vhosts/van-dijk.nu/vasr.van-dijk.nu/load.php(181): ActivityList::getNumberActivities()<br/>#1 /var/www/vhosts/van-dijk.nu/vasr.van-dijk.nu/index.php(2): require_once('...')<br/>#2 {main}