Error message

• Notice: Trying to access array offset on value of type null in calendar_plugin_row->render() (line 439 of 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 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 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 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 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 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 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 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 sites/all/modules/calendar/includes/calendar_plugin_row.inc).
• Notice: Undefined property: stdClass::$content in _print_generate_path() (line 678 of sites/all/modules/print/print.pages.inc).
• Notice: Trying to access array offset on value of type null in calendar_plugin_row->render() (line 439 of 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 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 sites/all/modules/calendar/includes/calendar_plugin_row.inc).