Why one of the new method that i add is not available on WCF Test Client?

I added a new method to an existing WCF service application. The method that I added returns a new class type.

When I start the WCF Test Client the new method is greyed out and I see that the reason that this method is greyed out is because this method is returning the new class type.

The method and the new class type are marked with DataContract & DataMember. There is no error - 开发者_运维知识库but next to the method name in the WCF test client I see the remark "this method is not available because it is using the class XXX" (XXX is the new class type that I defined).

When I call this new method from the silverlight client I get the same result that I expected with the same new class type.

Do you have weakly typed object data contract members, XMLNode, DataTable? The WCF test client does not support these