I have the same problem, did you manage to solve it?
Scanner was working fine under Windows 7, but when we upgraded to Windows 8.1 the scanner is not working. If I download drivers for 8.1, I can see the drivers installed, but the scanner won't show as a device in Xerox monitor and if I try to scan, it says No device is detected. If I try the drivers (1.2.5) for Windows 7, the device shows in Xerox monitor as conneceted, but I still cannot scan.
USB cable connected is the same as before and fully functioning, I have tried to disable firewall and connect the printer to other USB ports. Scanner still works fine on another Win XP computer.