Nie można wykonać zapytania do bazy

SELECT ek_issue.id, ek_issue.num_id, ek_issue.num_cont, ek_issue.num_year, ek_issue.from_e, ek_issue.to_e, ek_issue.lp_order, ek_pictures.picture, ek_pictures_note.note, MAX(ek_issue.num_cont) 
FROM ek_issue, ek_pictures LEFT JOIN ek_pictures_note ON (ek_pictures_note.picture = ek_pictures.picture AND ek_pictures_note.lang = 'pl')
WHERE ek_issue.available = '1'
AND ek_issue.on_special = '1'
AND ek_pictures.tag = 'issue'
AND ek_issue.id = ek_pictures.affiliation
GROUP BY ek_issue.id 
ORDER BY num_cont DESC 
LIMIT 1

MySQL Error: Expression #8 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'exit.ek_pictures.picture' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

Skrypt nie moze być wykonany.