Cannot serialize parameter of type '{0}' (for operation '{1}', contract '{2}') because it is not the exact type '{3}' in ...

Cannot serialize parameter of type '{0}' (for operation '{1}', contract '{2}') because it is not the exact type '{3}' in the method signature and is not in the known types collection. In order to serialize the parameter, add the type to the known types collection for the operation using ServiceKnownTypeAttribute.