# Misc notes

- Sometimes the midi_server's debug output shows an "Application -1 not registered" error message. This means it cannot figure out which app an incoming BMessage came from. The server ignores those messages.

  How can this happen? libmidi2 has two ways of sending messages to the midi_server: it either expects a reply back or not. In the first case, it is obvious to the midi_server what the reply address of the message is. In the second case, even though it is not necessary for the server to send a message back, it still uses the reply address to determine which app the message came from. For this, BMessenger uses be_app_messenger of the client app.

  However, if the client app has no BApplication object, there is no be_app_messenger either. Now, the midi_server cannot determine where the message came from and will ignore it. Is this important? For example, when such a client app Release()'s its endpoints, it sends a message to the server without a return address. Now the server ignores that message and does not remove the endpoint from the roster. Of course, after the client app has died, the endpoints will be removed eventually. Does all of this matter? Not really, because only trivial apps will have no BApplication object.