Ошибка jQueryxxxxxxx_xxxxxxxxxxx was not called

Получаю эту ошибку jQueryxxxxxxx_xxxxxxxxxxx was not called.

jQuery.ajax({ 
            type : "GET",
            url : 'https://xxx/api/postcode_v_1.php?id='+postcode+'',           
            dataType : "jsonp",

файл postcode_v_1.php возвращает:

{"0":"58859","id":"58859","1":"1822KC","code":"1822KC","2":"1822 KC","code_new":"1822 KC","3":"Leopoldstraat","straat":"Leopoldstraat","4":"1 t/m 71","nummers":"1 t/m 71","5":"Alkmaar","plaats":"Alkmaar","6":"Alkmaar","gemente":"Alkmaar","7":"Noord-Holland","region":"Noord-Holland"}

Содержит: header('Content-Type: application/json'); echo stripslashes(json_encode($row_post));