Windows 8.1 and earlier does not load USB serial port driver by default. Thus the 'MIDI Router' device is seen in erred state in Device Manager and no serial device appear although the device works fine. This happens because for these Windows versions one needs to explicitly specify that generic usbser.sys driver should be loaded for VID and PID of device. This behaviour is explained in detail at https://stackoverflow.com/questions/41541655/custom-usb-vid-pid-make-windows-7-8-automatically-choose-usbser-sys-driver
Solution: provide INF file. I've used sligtly modified a-star.inf mentioned above but to avoid installation warnings it needs to be signed by inf2cat tool that I do not have.
Windows 8.1 and earlier does not load USB serial port driver by default. Thus the 'MIDI Router' device is seen in erred state in Device Manager and no serial device appear although the device works fine. This happens because for these Windows versions one needs to explicitly specify that generic usbser.sys driver should be loaded for VID and PID of device. This behaviour is explained in detail at https://stackoverflow.com/questions/41541655/custom-usb-vid-pid-make-windows-7-8-automatically-choose-usbser-sys-driver
Solution: provide INF file. I've used sligtly modified a-star.inf mentioned above but to avoid installation warnings it needs to be signed by inf2cat tool that I do not have.