remove the double quotes of a subquery

if you find the field!
to correct the double quote and try pgadmin3 works.

This is the modified query and running

SELECT m.mat_anio_academico, mu.udi_id, u.udi_nombre, u.sem_codigo, u.udi_letra_nomina, mu.mud_nota_final, mu.mud_nota_recuperacion, m.mma_id FROM (SELECT DISTINCT ON (mud.udi_id) mud.mud_id FROM matricula_unidad_didactica AS mud INNER JOIN matricula AS m ON mud.mat_id=m.mat_id INNER JOIN alumno AS a ON m.alu_id=a.alu_id WHERE a.alu_id = 415 ORDER BY mud.udi_id DESC, "m"."mat_anio_academico" DESC) AS "mudi" JOIN "matricula_unidad_didactica" AS "mu" ON "mudi"."mud_id"="mu"."mud_id" JOIN "unidad_didactica" AS "u" ON "mu"."udi_id"="u"."udi_id" JOIN "matricula" AS "m" ON "mu"."mat_id"="m"."mat_id" JOIN "alumno" AS "a" ON "m"."alu_id"="a"."alu_id" WHERE "a"."alu_id" = 415 ORDER BY "u"."sem_codigo" ASC, "u"."udi_letra_nomina" ASC, "m"."mat_anio_academico" ASC