I'm using an macOS machine. I was working with my devices without any problem (Arduinos, external MIDI devices, etc.) until I installed the FTDI 2.4.2 drivers.
Suddenly, all my devices stop working. I uninstalled the FTDI drivers, unloaded the AppleFTDI kext, install the FTDI drivers, and so on.
Nothing happened.
I can't see the devices when I attach them to the machine. I know it is been seen by the computer because I can list them with lsusb. Also, I know that the FTDIUSBSerialDriver is loaded as is listed when I do a kextstat.
After a while...
I found the solution. I had the D2XX.kext from FTDI being loaded. It claims all the /dev/tty.*, so I needed to disable it. Now everything is working again.