SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: SELECT t.*, v.id AS isvoted FROM bb1_threads t LEFT JOIN bb1_votes v ON (v.id=t.threadid AND v.votemode=2 AND v.ipaddress='50.16.120.143') WHERE t.threadid = '968'
mysql error: Unknown column 'v.votemode' in 'on clause'
mysql error number: 1054
mysql version: 5.1.73-log
php version: 5.6.30
Date: 20.02.2017 @ 21:04
Script: /thread.php?goto=lastpost&threadid=968&sid=84ee90ab2198646be8043eb1f676158c
Referer: