Allen + Heath DB4 not showing up in OSX or Traktor
I’m running a 2015 Macbook Air with OSX 10.11.3 and have fully updated drivers and firmware for the soundcard on the DB4 (2.2.2 + 1.4.1 upgrade to firmware and 3.3.11 OSX drivers). The DB4 is connected properly - the hardware shows up in “About this Mac/System Profile” - but it is not recognized as a soundcard by the OS at all (not in Audio Midi Setup, not in Sound Preferences, not in Traktor or other sound programs).
Any idea what I’m doing wrong?
Oh yeah I should add, the DB4 shows up perfectly fine in other computers (a desktop running 10.12.2 and another laptop whose version of OS I forget). It’s just the Air that’s having the problem so I suspect a faulty driver installation but what would I look for and how would I fix it? I’ve reinstalled the driver a couple times (even using the DB4 uninstall tool first) but to no avail.
Serato has a good step by step guide on what to do when the audio interface (controller) is not detected by the OSX, this is basically the same thing. 
Any idea where to find that guide? Thanks!