Software error:

DBD::mysql::db selectcol_arrayref failed: Unknown column 'bugs.issue_type' in 'where clause' [for Statement "SELECT bugs.bug_id AS bug_id, bugs.bug_status AS bug_status, bugs.priority AS priority, CASE WHEN INSTR(CAST(map_assigned_to.login_name AS BINARY), CAST('@' AS BINARY)) != 0 THEN SUBSTR(map_assigned_to.login_name, 1, INSTR(CAST(map_assigned_to.login_name AS BINARY), CAST('@' AS BINARY)) - 1) ELSE map_assigned_to.login_name END AS assigned_to
  FROM bugs
LEFT JOIN bug_group_map AS security_map ON bugs.bug_id = security_map.bug_id
INNER JOIN profiles AS map_assigned_to ON bugs.assigned_to = map_assigned_to.userid
INNER JOIN bug_status AS map_bug_status ON bugs.bug_status = map_bug_status.value
INNER JOIN priority AS map_priority ON bugs.priority = map_priority.value
 WHERE bugs.creation_ts IS NOT NULL
   AND  (security_map.group_id IS NULL OR security_map.group_id IN (-1))
   AND INSTR(CAST(bugs.short_desc AS BINARY), CAST('[68cat]' AS BINARY)) > 0 AND  bugs.issue_type IN ('ENHANCEMENT') 
GROUP BY bugs.bug_id
ORDER BY map_bug_status.sortkey, map_bug_status.value, map_priority.sortkey, map_priority.value, assigned_to, bug_id
LIMIT 500
"] at Bugzilla/Search.pm line 711.
	Bugzilla::Search::data(Bugzilla::Search=HASH(0x56177374c5c0)) called at /var/www/bugzilla-nb/buglist.cgi line 760

For help, please send mail to the webmaster (users@infra.apache.org), giving this error message and the time and date of the error.