[tareqbd]

We keep getting this error at least once per day. Please advise how to fix this.

Database error in vBulletin 4.2.2:

Invalid SQL:
SELECT * FROM post_thanks AS post_thanks INNER JOIN user AS user USING (userid) WHERE post_thanks.postid IN () ORDER BY post_thanks.username ASC;

MySQL Error : 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 ') ORDER BY post_thanks.username ASC' at line 1
Error Number : 1064
Request Date : Wednesday, January 20th 2016 @ 01:20:28 PM
Error Date : Wednesday, January 20th 2016 @ 01:20:28 PM
Script : http://www.domain.tld/private.php?do=showpm&pmid=xxxx
Referrer : http://www.domain.tld/private.php
IP Address : xx.xx.x.xx
Username : username
Classname : vB_Database
MySQL Version :