You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AND lang = "en" ORDER BY titulo ASC' at line 1
En el query:
SELECT * FROM mrp_contenidos WHERE habilitado = 1 AND borrado = 0 AND fk_id_mrp_contenidos_categorias = AND lang = "en" ORDER BY titulo ASC