MWS Merchant Fullfillement API GetEligibleShippingServices抛出500错误

Question

我正在使用Fullfillement API的C＃库。当它试图这样做时

HttpWebResponse httpResponse = request.GetResponse() as HttpWebResponse

它抛出Web异常。以下是响应xml。

<?xml version="1.0"?>
<ErrorResponse xmlns="https://mws.amazonservices.com/MerchantFulfillment/2015-06-01">
  <Error>
    <Type>Receiver</Type>
    <Code>InternalFailure</Code>
  </Error>
  <RequestId>e278b575-a183-43d7-a50d-a877a6212a00</RequestId>
</ErrorResponse>

可能是根本原因？