I (probably) had similar problem. Your Akai keyboard is mentioned twice in the list, one is reciever and the other is transmitter. You are trying to use reciever because it's first, but you really want just the other one.
I made this quick fix to MidiKeyboard class, row 107 (?), I added code in red:
if(d.getName().contains(deviceName) && device.getMaxTransmitters() == -1)
I'm not sure if it is a good way how to indentify transmitter but it works for me.