Library no longer working with updated API

[ghost]

I'm getting this error message when try to retrieve contact with parameters ContactID:

<ApiException xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <ErrorNumber>0</ErrorNumber> <Message>Operator '==' incompatible with operand types 'Guid' and 'String'</Message> </ApiException> and when retrieve contact by using other parameters ("Name" etc), no information is returned: <Response xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <Id>6c5fbf40-0af2-4326-97eb-b384693f1e3b</Id> <Status>OK</Status> <ProviderName>SXI-SHOPP XERO Private Integrator</ProviderName> <DateTimeUTC>2010-08-14T09:13:05.7253215Z</DateTimeUTC> </Response> It was working before and this suddenly happened!

[ghost]

And when put a new contact, invoice or payment, I get this message back: An error occurred in Xero please contact [email protected]. (ErrorNumber 500) Put the same input xml works correctly with API Previewer in api.xero.com