Created attachment 765 [details]
Simple solution demonstrating the issue
WCF service that returns a derived type. The derived types is registered on the ServiceContract using the ServerKnownTypes attribute.
When the concrete type (the one that is actually returned by the service) is a DataContract with a namespace, the WCF client crashes on Linux/Mono 2.10.6:
System.Runtime.Serialization.SerializationException: Unknown type Common.BaseReturnType is used for DataContract with reference of name [...] derived types of a data contract or data member should be added to known types
Moving the namespace from the concrete type, to one of the base types fixes the problem.
The code runs successfully 'as is' on Microsoft .NET 4.0.
See attached solution for illustration of the issue.
- Run the Server.exe project and wait for the server to start. I ran this on my Windows PC / .NET 4.0
- Run the WCFKnownTypes.exe client on a Linux machine running Mono 2.10.6
The client will crash with the above error.
If you move the namespace from the ConcreteReturnType DataContractAttribute to the DerivedReturnType or BaseReturnType DataContractAttribute, it will work.