When using your Scanner plugged in to a USB hub, any scan that it makes is just a black page.
You may notice if you lift up the scanner lid that the scanner light is not on.
There is either not enough power supplied to the hub or the bulb has blown.
Plug the scanner into a powered USB hub and check the connection.
You can also plug it into one of the computer’s USB ports so that it is directly connected.
If that does not work then the scanner may need repair.