An item with the same key has already been added.
System.Xml.Xsl.XslTransformException: An error occurred during a call to extension function 'RegisterProduct'. See InnerException for a complete description of the error. ---> System.ArgumentException: An item with the same key has already been added. at Interprise.Facade.Customer.ItemTaxFacade.CalculateTax(String customerCode, String itemCode, String umCode, Decimal netSalesPrice, Decimal netSalesPriceRate, Decimal cost, Decimal costRate, Decimal quantity) at AspDotNetStorefrontCommon.InterpriseHelper.GetSalesPriceAndTax(String customerCode, String itemCode, String currencyCode, Decimal quantity, String unitMeasureCode, Boolean withVAT, Decimal& promotionalPrice, Decimal& vat) in d:\Websites\AspDotNetStorefrontIS485\ASPDNSFCommon\Interprise.cs:line 1437 at AspDotNetStorefrontCommon.InterpriseHelper.GetSalesPriceAndTax(String customerCode, String itemCode, String currencyCode, Decimal quantity, String unitMeasureCode, Boolean withVAT, Decimal& promotionalPrice) in d:\Websites\AspDotNetStorefrontIS485\ASPDNSFCommon\Interprise.cs:line 1165 at AspDotNetStorefrontCommon.DTO.ProductPricePerUnitMeasure.GetAll(String itemCode, Customer forCustomer) in d:\Websites\AspDotNetStorefrontIS485\ASPDNSFCommon\DTO\ProductPricePerUnitMeasure.cs:line 98 at AspDotNetStorefrontCommon.XSLTExtensionBase.RegisterProduct(Int32 itemCounter, String itemCode, String itemType) in d:\Websites\AspDotNetStorefrontIS485\ASPDNSFCommon\XSLTExtensionBase.cs:line 2785 --- End of inner exception stack trace --- at System.Xml.Xsl.Runtime.XmlExtensionFunction.Invoke(Object extObj, Object[] args) at System.Xml.Xsl.Runtime.XmlQueryContext.InvokeXsltLateBoundFunction(String name, String namespaceUri, IList`1[] args) at