model plugin doesn't receive data from a subscribed topic
I have a problem and I think it comes from a stupid mistake, but I am not able to find it.
I have a world and a model plugin and data has to be exchanged. So I use the message system to send and receive messages. It works fine, both plugins are loaded and the model plugin sends a message to the world plugin. The data is received and the world plugin sends some data back. But the callback-function of the model plugin is never called.
Can you take a quick look and tell me what I did wrong? Here is the code code