MIDI NoteOn/Off not recognised?

[LFSaw]

it it just me?

MKtl(\lctl, "novation-launchcontrol" ).trace(true).gui;
MKtl(\lctl).desc.openFile;

• the GUI does not show the buttons (NoteOnOff events), although they are defined in the desc.
• when pushing a button MKtl complains:

MKtl('lctl') : unknown 'noteOn' element found at midiNum: 9,  midiChan 0.
    Please add it to the description file. E.g. for a button:<bt>: (midiMsgType: 'noteOn', elementType: <'button'>, midiChan: 0, midiNum: 9, spec: <'midiBut'>, mode: <'push'>)

MKtl('lctl') : unknown 'noteOff' element found at midiNum: 9,  midiChan 0.
    Please add it to the description file. E.g. for a button:<bt>: (midiMsgType: 'noteOff', elementType: <'button'>, midiChan: 0, midiNum: 9, spec: <'midiBut'>, mode: <'push'>)

Buttons are defined in desc via

// ...
(
    key: \bt,
    shared: ('elementType': 'pad', 'spec': 'midiNote', \ioType: \inout),
    elements: ((9..12) ++ (25..28)).collect{|num, i|
        (
            key: (i+1).asSymbol,
            groupType: \noteOnOffBut,
            shared: (
                groupType: \noteOnOffBut,
                midiNum: num,
                style: ( row: 2, column: i )
            )
        )
    }
),
/ ...

[LFSaw]

note that #301 seems to be related but is not. contrary to what is said there, noteOnOff elemets are not showing up at all.