171vr.cn - Database Error

(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 'FORCE INDEX (digest) WHERE t.`fid`='2' AND t.`displayorder` IN('0','1','2','3',' at line 1

SELECT * FROM forum_thread t LEFT JOIN forum_typeoptionvar f ON f.tid = t.tid FORCE INDEX (digest) WHERE t.`fid`='2' AND t.`displayorder` IN('0','1','2','3','4') AND t.`lastpost`>='1713471714' AND t.`sortid`='1' AND t.`digest`>'0' and optionid=30 ORDER BY value DESC LIMIT 20

PHP Debug

No.	File	Line	Code
1	forum.php	71	require(%s)
2	source/module/forum/forum_forumdisplay.php	657	table_forum_thread->fetch_all_search_byoptionid(Array, %d, %d, %d, %s, %s, %s)
3	source/class/table/table_forum_thread.php	581	discuz_database::fetch_all(%s)
4	source/class/discuz/discuz_database.php	101	discuz_database::query(%s, Array, false, false)
5	source/class/discuz/discuz_database.php	137	db_driver_mysqli->query(%s, false, false)
6	source/class/db/db_driver_mysqli.php	147	db_driver_mysqli->halt(%s, %d, %s)
7	source/class/db/db_driver_mysqli.php	222	break()

Discuz! Database Error