hi there, I have an even more peculiar niche issue … running a Hackintosh with 10.10.5 installed. Did not even have the AppleFTDI kext installed it seems (or at least sudo mv AppleUSBFTDI.kext AppleUSBFTDI.disabled did not give any result), does have the OEM FTDI installed now. Seems that this Shuttle SX79R5 might need a particular kext of its own for this to work ?
launchctl list | grep serialosc returns
406 0 org.monome.serialosc
ls -l /dev/tty.usbserial-* returns
ls: /dev/tty.usbserial-*: No such file or directory
ls -lrt /dev | grep usbserial returns nothing, just a new bash line
kextstat -l | grep -i ftdi used to return something like below, but since running the ftdi drivers it no longer returns anything.
131 0 0xffffff7f828a5000 0x7000 0x7000 com.apple.driver.AppleUSBFTDI (1.0.1b16) <110 42 5 4 3>
serialosc and -detector are both running.
Another thing maybe worth mentioning is that the monome does show up fine in the system profiler usb list. (and works without problems on other machines here, just need to get it going on this particular machine which will go on the road for live performances)
Have to say, all other USB devices, soundcards, midi controllers, etc run without any problems. (and I did try moving it from the usb hub to the other usb ports on the machine; no go)

Any pointers much appreciated !
(update 1)
indeed, these kexts are loaded
AppleUSBAudio.kext
AppleUSBDisplays.kext
AppleUSBEthernetHost.kext
AppleUSBMultitouch.kext
AppleUSBTopCase.kext
and
FTDIUSBSerialDriver.kext
(update 2)
I downloaded the 2.4.2 FTDI drivers from https://www.ftdichip.com/Drivers/VCP/MacOSX/FTDIUSBSerialDriver_v2_4_2.dmg
removed the previous FTDI and installed the 2.4.2
kextstat -l | grep -i ftdi now returns
111 0 0xffffff7f818c4000 0x7000 0x7000 com.apple.driver.AppleUSBFTDI (1.0.1b16) <110 42 5 4 3>
122 0 0xffffff7f8283d000 0x7000 0x7000 com.FTDI.driver.FTDIUSBSerialDriver (2.4.2) <110 42 5 4 3 1>
I can’t find the AppleUSBFTDI that seems to be loaded anywhere … ?
kextstat_result.txt (11.8 KB)
(update 3)
mmm, clean installed a new system, 10.12.6 – same issue …
(update 4)
mmm, decided to try it on my mac pro 5,1 - also running 10.12.6 – same issue …
could it have anything to do with my device being a 40h ?