Hi Thijs,

From your description, I believe what is happening is a mix of 2 things

Your remote element is probably replying with an object of type Message and not IInterAppCall and most likely the QAction where you parse this is using something like

IInterAppCall interApp = InterAppCallFactory.CreateFromRaw(rawData);

This will try to create an IInterAppCall type to work around this you can send the response message as IInterAppCall as well or use the following code

Message message = MessageFactory.CreateFromRaw(rawData);

The second thing that could be causing you issues is that although the Message objects have the same namespaces in both connectors, the InterAppCallFactory could be having issues loading it in memory correctly or having some ambiguous reference

To work around this you can also try the following (IInterAppCall)

var myCustomSerializer = SerializerFactory.CreateInterAppSerializer(typeof(IInterAppCall), new List<Type>{typeof(Skyline.Protocol.IAC.MyCustomObjectMessage)});
var interApp = InterAppCallFactory.CreateFromRaw(rawData, myCustomSerializer);

Or (Message)

var myCustomSerializer = SerializerFactory.CreateInterAppSerializer(typeof(Message), new List<Type>{typeof(Skyline.Protocol.IAC.MyCustomObjectMessage)});
var message = MessageFactory.CreateFromRaw(rawData, myCustomSerializer);