Database error in vBulletin 3.6.7:

Invalid SQL:

SELECT user.avatarid, user.avatarrevision, avatarpath, NOT ISNULL(customavatar.userid) AS hascustom, customavatar.dateline,
customavatar.width, customavatar.height
FROM user AS user
LEFT JOIN avatar AS avatar ON avatar.avatarid = user.avatarid
LEFT JOIN customavatar AS customavatar ON customavatar.userid = user.userid
WHERE user.userid =;

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 '' at line 6
Error Number : 1064