You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')                 AND 1=1         

GROUP BY id_prop

 ORDER BY id_prop DESC
...' at line 53<hr>

SELECT

    properties_loc1.name_en_loc1 AS country,
    CASE WHEN properties_loc2.name_en_loc2 IS NOT NULL THEN properties_loc2.name_en_loc2 ELSE province1.name_en_loc2  END AS province,
    CASE WHEN properties_loc3.name_en_loc3 IS NOT NULL THEN properties_loc3.name_en_loc3 ELSE areas1.name_en_loc3  END AS area,
    CASE WHEN properties_loc4.name_en_loc4 IS NOT NULL THEN properties_loc4.name_en_loc4 ELSE towns.name_en_loc4  END AS town,
    CASE WHEN properties_types.types_en_typ IS NOT NULL THEN properties_types.types_en_typ ELSE types.types_en_typ END AS type,
    properties_properties.descripcion_en_prop  as descr,
    properties_status.status_en_sta as sale,
    properties_properties.referencia_prop as ref,
    properties_properties.m2_prop,
    properties_properties.m2_parcela_prop as m2p_prop,
    properties_properties.m2_balcon_prop as m2_balcon_prop,
    properties_properties.precio_prop as old_precio,
    properties_properties.preci_reducidoo_prop as precio,
    properties_properties.habitaciones_prop,
    properties_properties.aseos_prop,
    properties_properties.piscina_prop,
    id_prop,
    REPLACE(image_img, 'https', 'http') AS image_img,
    properties_properties.vendido_prop,
    properties_properties.reducido_prop,
    properties_properties.nuevo_prop,
    properties_properties.cerca_mar_prop,
    properties_properties.vistas_mar_prop,
    properties_properties.exclusivo_prop,
    properties_properties.piscina_prop,
    properties_properties.golf_prop,
    properties_properties.embargo_prop,
    properties_properties.aseos2_prop,
    properties_properties.alquilado_prop,
    properties_properties.reservado_prop,
    properties_properties.watermark_prop,
        title_en_prop as metatitle



    FROM properties_loc4 towns
    LEFT OUTER JOIN properties_properties ON properties_properties.localidad_prop = towns.id_loc4
    LEFT OUTER JOIN properties_loc3 areas1 ON towns.loc3_loc4 = areas1.id_loc3
    LEFT OUTER JOIN properties_loc3 ON areas1.parent_loc3 = properties_loc3.id_loc3
    LEFT OUTER JOIN properties_loc2 province1 ON areas1.loc2_loc3 = province1.id_loc2
    LEFT OUTER JOIN properties_loc2 ON province1.parent_loc2 = properties_loc2.id_loc2
    LEFT OUTER JOIN properties_loc1 ON province1.loc1_loc2 = properties_loc1.id_loc1
    LEFT OUTER JOIN properties_loc4 ON towns.parent_loc4 = properties_loc4.id_loc4
    LEFT OUTER JOIN properties_types types ON properties_properties.tipo_prop = types.id_typ
    LEFT OUTER JOIN properties_types ON types.parent_typ = properties_types.id_typ
    LEFT OUTER JOIN properties_images ON properties_properties.id_prop = properties_images.property_img AND order_img = 1
    LEFT OUTER JOIN properties_status ON properties_properties.operacion_prop = properties_status.id_sta

WHERE  activado_prop = 1 

      AND CASE WHEN properties_types.id_typ IS NOT NULL THEN properties_types.id_typ ELSE types.id_typ END IN (54/)                 AND 1=1         

GROUP BY id_prop

 ORDER BY id_prop DESC

LIMIT 0, 9