Re: [Libusbx-devel] Getting "unsupported API call for 'open'" on Windows 8.1 libusb

[Xiaofan C. <xia...@gm...>]

On Wed, Jul 30, 2014 at 5:28 AM, Bob Tausworthe <to...@se...> wrote:
> Sorry to trouble you but I've exhausted other options. We are developing a
> composite HID/debug interace device and are using libusb 1.0 under 32 bit
> Cygwin to access the debug interface portion. Everything is working fine on
> Windows 7 and Linux but when we try to run the application on Windows 8, it
> fails with the error :
>
> libusb: debug [unsupported_open] unsupported API call for 'open'
> (unrecognized device driver)
> libusb: debug [libusb_open] open 2.16 returns -12
> ERROR: Unable to open usb device
>
> After reading some posts of people with similar issues, I tried all of the
> drivers Zadig supports but didn't see any difference in behavior. I have
> tried building under Win7 and Win8 but the results are the same. I am using
> version 1.0.18 of libusb. The trace below was taken with the WinUSB driver
> version 6.1.7600.16385.
>

libusbx is no longer been updated since it has merged back to libusb.
You should try libusb-1.0.19 first to see if that helps.
http://sourceforge.net/projects/libusb/files/libusb-1.0/

-- 
Xiaofan