DB ERROR 1055

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Page URL: https://chosogia.com/canon-70d-18-135mm
Script Info: block_product_details.php
Database error: Invalid SQL: SELECT fg.group_id,fg.group_name,f.feature_name, GROUP_CONCAT(DISTINCT f.feature_value ORDER BY f.feature_value DESC SEPARATOR ' / ') as feature_value, #f.feature_value, f.unit FROM va_features f, va_features_groups fg WHERE f.group_id=fg.group_id AND f.item_id=4922003 AND fg.show_on_details=1 AND (f.show_on_details=1 OR f.show_as_group=1) GROUP BY fg.group_id,f.feature_name ORDER BY fg.group_order,fg.group_id, f.feature_id ASC
MySQL Error: Expression #5 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'chosogia.f.unit' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by