question

I apologize, it's a little difficult for me to follow the logic of your model, so I don't know if this is the direction you want to take your model, but it seems that since you are controlling the logic of the dispatcher with messages, that instead of calling to free the TE when the other passes NN16, that you'd rather control that logic by also sending message to the dispatcher and controlling the freeing and aquiring of the TEs that way. Again, I'm not entirely sure whether that's the direction you want to go, you obviously know your model a lot better than me..

However, as for freeing up the TE, I noticed that in your code you call freeoperators(TE, NULL). You have the "involved" parameter as NULL which seems to be the problem here. Instead I changed it to freeoperators(dispatcher, TE). And that seems to free up the TE sitting at NN2. However then it seems to move over to NN16 while the other two TEs continue working on the Queues. So I'm not sure if that's what you want them to do, you may need to check the logic of the model at that point, but it does seem to at least resolve the problem of your TE not being freed.