LED not on when hard disk is seated

For my USB3-SATA-UASP1, when the hard disk is seated, and the power is turned on, the LED light is turned off (black), but when I remove the hard disk, the LED light turns blue, which is inconsistent with your FAQ: http://plugable.com/products/usb3-sat… .

My computer, which is only a few months old, is not recognizing the hard disk - is the LED light not being on when the hard disk is seated and indication that the plugable unit is not operating properly?

Also, when I plug in the device and seat the drive on an older computer, Windows 8 starts the process of installing device drivers and then I get an error that says “Device Unplugged”