An AJAX HTTP error occurred. HTTP Result Code: 500

The following error occurred while edit the view.

An AJAX HTTP error occurred.
HTTP Result Code: 500
Debugging information follows.
Path: /atni-dev/admin/structure/views/view/calendar/preview/page_1/ajax
StatusText: error
ResponseText: PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DESC, nid IN () DESC, nid = 0 DESC, H.repeat_end_date DESC, H.date ASC' at line 6: SELECT H.instance_id AS instance_id, H.nid AS nid, H.date AS date, H.start_time AS start_time, H.end_time AS end_time, H.notice AS notice, H.repeat_rule AS repeat_rule, H.repeat_end_date AS repeat_end_date, H.original_instance_id AS original_instance_id, H.customised AS customised, H.slot_length AS slot_length, DATEDIFF(H.date, :time_start ) AS day, CASE
WHEN H.nid = :primary_id THEN '1'
WHEN H.nid IN ( :secondary_id ) THEN '2'
WHEN H.nid = :tertiary_id THEN '3'
ELSE '0'
END AS type
FROM
{opening_hours} H
WHERE (( (nid IS NULL ) OR (nid IN (:db_condition_placeholder_0)) OR (nid IS NULL ) )AND(( (H.repeat_end_date IS NULL ) AND (H.date BETWEEN :db_condition_placeholder_1 AND :db_condition_placeholder_2) )OR( (H.repeat_end_date IS NOT NULL ) AND (CONCAT(H.date, ' ', H.start_time) BETWEEN :time_start AND :time_end) )))
ORDER BY nid = DESC, nid IN () DESC, nid = 0 DESC, H.repeat_end_date DESC, H.date ASC; Array
(
[:db_condition_placeholder_0] =>
[:db_condition_placeholder_1] => 2016-07-31 00:00:00
[:db_condition_placeholder_2] => 2016-09-03 00:00:00
[:time_start] => 2016-07-31 00:00:00
[:time_end] => 2016-09-03 00:00:00
[:primary_id] =>
[:secondary_id] =>
[:tertiary_id] =>
)
in booking_timeslots_get_daily_settings() (line 1481 of /sites/all/modules/contrib/booking_timeslots/booking_timeslots.module).