message before Event List

Thank you for your pluggin.
When I put the shortcode [event_rocket_list] in one of my pages, before que list of events, apears this message:

Warning: array_merge(): Argument #2 is not an array in /homepages/16/d491947935/htdocs/wp-content/plugins/event-rocket/inc/shortcodes.php on line 77

What happens?
Thank you.

https://wordpress.org/plugins/event-rocket/