Cannot use MIDI devices

Hi all,
I’m trying to use MIDI Devices to send Midi from Unreal to Ableton. However I always get the following error:

LogMIDIDevice: Warning: Failed to bind to MIDI device ‘IAC-Treiber BUS1’ (ID: 0): Device not setup to receive MIDI

I also get it with real midi hardware drivers from my focusrite interface.