An error with Conversations

[birdfeedr]

I created a test thread which generated the error with the modification. I will drop sql_mode restrictions and test again.

Code:

Type: 20
File:  (Line no. 0)
Message
SQL Error: 1055 - Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'hlf_dbHLFv2.c.uid' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
Query:
SELECT * FROM (
               SELECT           p.cid,
                                c.uid,
                                GROUP_CONCAT(p.uid) AS puids,
                                c.subject
               FROM            mybb_cnv_conversations c
               LEFT OUTER JOIN mybb_cnv_participants p
               ON              p.cid = c.cid
               WHERE           c.subject = 'New Reply to thread subscription test 4'
                               AND
                               c.uid IS NULL
               GROUP BY p.cid
              ) innerqry
WHERE puids = '1384'
ORDER BY cid DESC
LIMIT 1