Order_carrier NullReferenceException error

[GiorgioConte]

Hi,
when i try to call the .get() method for order_carrierFactory, i receive an NullReferenceException error on deserialize class.

Here my code snippet:
OrderCarrierFactory OFOrderCarrier = new
OrderCarrierFactory(BaseUrl.ToString(), AccountRW.ToString(), Password);
order_carrier OrdineTrack = OFOrderCarrier.Get(13); <--------

Here the error:
System.NullReferenceException non è stata gestita dal codice utente
HResult=-2147467261
Message=Riferimento a un oggetto non impostato su un'istanza di oggetto.
Source=Bukimedia.PrestaSharp
StackTrace:
in Bukimedia.PrestaSharp.Deserializers.PrestaSharpDeserializer.GetElementByName(XElement root, XName name) in \Git\PrestaSharp\Deserializers\PrestaSharpDeserializer.cs:riga 391
in Bukimedia.PrestaSharp.Deserializers.PrestaSharpDeserializer.Map(Object x, XElement root) in i\Git\PrestaSharp\Deserializers\PrestaSharpDeserializer.cs:riga 97
in Bukimedia.PrestaSharp.Deserializers.PrestaSharpDeserializer.Deserialize[T](IRestResponse response) in i\Git\PrestaSharp\Deserializers\PrestaSharpDeserializer.cs:riga 55
in RestSharp.RestClient.Deserialize[T](IRestRequest request, IRestResponse raw)
InnerException:

Can u help me?
Regards

[EduLeonPavon]

Hello @GiorgioConte
First all, thank you for your feedback. Please, tell me if the the order_carrier exists in the affected tables in PrestaShop.
Regards.

[GiorgioConte]

Hi @EduLeonPavon,
according to official prestashop db schema (http://doc.prestashop.com/display/PS16/Fundamentals+of+PrestaShop+Development#FundamentalsofPrestaShopDevelopment-Databaseschema) there's a table named ps_order_carrier.
And webservice api confirm that with this schema (http:///api/order_carriers)

<order_carrier>

<id_order/>
<id_carrier/>
<id_order_invoice/>

<shipping_cost_tax_excl/>
<shipping_cost_tax_incl/>
<tracking_number/>
<date_add/>
</order_carrier>