If you are talking about the AppleUSBFTDI driver, yes we've done that. Not doing that would give us a different error which was not as complicated as what we're facing now. We used either the D2XX helper or "kextunload" to do that and we also used "kextstat | grep FTDI" to double-check.

Hi,

We are currently having some issues with the FT245RL chip which communicates with an FPGA. We have our own software to use that chip to send data to our computer, but our computer can't get any data. We saw Ft_SetFlowControl failed. Our computer is currently running macOS High Sierra 10.13.5, and the same computer with the same software worked well in the past when it was running Sierra 10.12.3. We've tried two versions of D2XX drivers (we're using direct drivers), 1.4.4 (old) and 1.4.24 (latest), getting the same problem.

We also tested the "simple" code under /Samples/Simple in the driver package (which just writes some data to the chip and then reads the data back), and even that code ran into errors. The number of bytes in D2XX receive-queue was always a zero or a bunch of zeros and the readings were just junk. We tried this piece of simple code on several different computers running macOS Sierra 10.12.6, High Sierra 10.13.5, and Catalina 10.15.7. All of them showed similar results. We also tried another board that has the same design and we still got the same result.

Does anyone have any idea on how to fix this? Thanks in advance!