Try putting the dataset in a DataContract.

>Hi Kevin,
>
>I am trying to use the MM Business Objects 2.4 with WCF and I am returing Dataset on one of my OperationContract, but some how I am getting SerializationException: error. Any idea why or do I need to wait for MM.NET 3.0 to use Oakleaf business objects.
>
>

>   <ExceptionString>System.Runtime.Serialization.SerializationException: Type 'OakLeaf.MM.Main.Data.mmDataSet' with data contract name 'mmDataSet:http://schemas.datacontract.org/2004/07/OakLeaf.MM.Main.Data' is not expected. Add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to DataContractSerializer.
>   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeAndVerifyType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, Boolean verifyKnownType)
>   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithXsiTypeAtTopLevel(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj)
>   at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph)
>   at System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph)
>   at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph)
>   at System.Runtime.Serialization.XmlObjectSerializer.WriteObject(XmlDictionaryWriter writer, Object graph)
>   at System.ServiceModel.Dispatcher.DataContractSerializerOperationFormatter.SerializeParameterPart(XmlDictionaryWriter writer, PartInfo part, Object graph)</ExceptionString>
>
>

>
>Thanks
>Yassin