I'm trying to use the GetCategories method in the Trading API . I've had success invoking a couple of methods in the Finding API.

Here's the relevant information in my web.config file endpoint address="https://api.ebay.com/ws/api.dll" binding="basicHttpBinding" bindingConfiguration="eBayAPISoapBinding" contract="eBayTradingApi.eBayAPIInterface" name="eBayAPI"

 binding name="eBayAPISoapBinding"
       security mode="Transport" 
     binding

This is the raw request I'm able to retrieve using fiddler: POST https://api.ebay.com/ws/api.dll HTTP/1.1 Content-Type: text/xml; charset=utf-8 X-EBAY-API-COMPATIBILITY-LEVEL: 899 X-EBAY-API-DEV-NAME: 2d433616-XXXX-4391-93bb-f2e5592ba372 X-EBAY-API-APP-NAME: XXXXXMar-XXXX-4c87-9695-c622b673d9db X-EBAY-API-CERT-NAME: fa52b2d4-XXXX-48e3-afb9-c9d7f90ce917 X-EBAY-API-SITEID: 0 X-EBAY-API-CALL-NAME: GetCategories VsDebuggerCausalityData: uIDPozlSyi3Cwg5FpfFme+sJlqQAAAAAgOksZJ/2b0qjkJXXJFNRuSD4lYs8Zq5MhBHDeq6S+UQACQAA SOAPAction: "" Host: api.ebay.com Content-Length: 1410 Expect: 100-continue Accept-Encoding: gzip, deflate Connection: Keep-Alive

xyz

With the exception of the empty SOAPAction header and the VSDebuggerCausalityData header, it's pretty much identical to what I'm seeing in the API Test tool.

This is the error message I'm getting back:

2014-11-14T06:44:06.202ZFailureXML Parse error.XML Error Text: "; nested exception is: org.xml.sax.SAXParseException: The prefix "s" for element "s:Header" is not bound.". 5 Error ; nested exception is: org.xml.sax.SAXParseException: The prefix "s" for element "s:Header" is not bound. RequestError 895 E895_CORE_APICATALOG_17257396_R1

Based on the error message I'm getting back "The prefix "s" for element "s:Header" is not bound."; one could assume that the issue is with .net not generating a proper SOAP message, when indeed it is.

Please help!!!