as your screenshot shows, the available midi devices are 3,4,5 though
3rd time: you can find out your midi device number with the list_devices script
so did you try to edit the file with the actual number of your midi device? as I wrote earlier, you can retrieve the device ids with the list_devices script.
apparently the midi.xml is missing in the application bundle, therefore just copy this one as "midi.xml" into your Resources folder inside: https://github.com/mkalten/reacTIVision/blob/1.5.x/midi/demo.xml hint: right-click on reacTIVision.app and "Show Package Contents"
place this file as midi.xml into the Resources folder inside the application bundle https://github.com/mkalten/reacTIVision/blob/1.5.x/midi/demo.xml and/or edit the reacTIVision.xml file there pointing to an alternative path of your actual configuration file
... and you can list the available midi device number with the included script
the default midi configuration file is now inside the application bundle in the Resources folder
try these two: <capture width="640" height="480" fps="60" compress="true"/> <capture width="800" height="600" fps="max" compress="true"/>