Se ha producido un error al hacer la query.

select tareas.fld_titulo as area, group_concat(tsubareas.fld_titulo SEPARATOR ':::') as subarea from rarticulosrelacionados inner join tarticulosidioma tsubareas on tsubareas.idarticulo = rarticulosrelacionados.idarticulorelacionado inner join rarticulosarbol on rarticulosarbol.idarticulo = tsubareas.idarticulo inner join tarticulosidioma tareas on tareas.idarticulo = rarticulosarbol.idarticulopadre where rarticulosrelacionados.idarticuloprincipal = 51213 and idtiporelacionado = 213 and tareas.fld_publico_1 = 1 and tsubareas.fld_publico_1 = 1 group by tareas.idarticulo order by tareas.fld_titulo, tsubareas.fld_titulo

El error es:

Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'qvb714.tareas.fld_titulo' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by