Error message

• Notice: Trying to access array offset on value of type null in calendar_plugin_row->render() (line 439 of /var/www/chapters.shrm.org/sites/all/modules/calendar/includes/calendar_plugin_row.inc).
• Notice: Trying to access array offset on value of type null in calendar_plugin_row->render() (line 439 of /var/www/chapters.shrm.org/sites/all/modules/calendar/includes/calendar_plugin_row.inc).
• Notice: Trying to access array offset on value of type null in calendar_plugin_row->render() (line 439 of /var/www/chapters.shrm.org/sites/all/modules/calendar/includes/calendar_plugin_row.inc).