Authorize.Net SDK Error - "There was an error generating the XML document"

[ShadowDancerLV]

I'm using the following environment:

• Nuget package of the SDK (2.0.1 - https://github.com/AuthorizeNet/sdk-dotnet)
• C#
• Visual Studio 2019
• Sandbox accounts using test cards and zipcodes.

The request is successfully built however when I call the following code:

_oTranController = new AuthNetControllers.createTransactionController(apiRequest: _oTranRequest);
_oTranController.Execute();
_oResponse = _oTranController.GetApiResponse();

The response object is NULL

I get the exception There was an error generating the XML document

Nothing shows up anywhere else, just that error.

Any help appreciated.

[ShadowDancerLV]

Additional details:

BaseUrl: https://test.authorize.net
CardPresentUrl: https://test.authorize.net
XmlBaseUrl: https://apitest.authorize.net

[ShadowDancerLV · Accepted solution]

Solution founds. 

Following fixes:

1. paymentType needed to be the actual  creditcard variable not an enumerator type.

               _paymentType = new AuthNetContract.paymentType
                {
                    Item = _creditCardType
                };

2. The expirationdate was returning 4 digit year instead of 2 digit year.