Getting the error message: MidiInAlsa::alsaMidiHandler: unknown MIDI input error!

So I've installed the drivers for samplerbox as per instructions on the github page, plugged in my AKAI MPD24 (which it appears to recognise)

Opened audio device #2
Opened MIDI: Akai MPD24 24:0
Opened MIDI: Akai MPD24 24:1
Opened MIDI: Akai MPD24 24:2
Preset loading: 0 (0 Saw)
Preset loaded: 0

but and am getting the error message:

MidiInAlsa::alsaMidiHandler: unknown MIDI input error!

I then tried this with my Alesis QX49, same issue...

Any ideas? I tried googling this message but most of posts point to this error being thrown when you have more than one device connected (which am I not doing..)