Mostly with those USB powered drives. This is not a bug but a limitation of the USB power available. You may find a powered USB hub can help.
Bob
i got 3 usb ports and for some reason i can use only two at a time... once i plugin the third the device is not recognized. it gives me some msg of unknown device or smth of the kind. doesn't matter how i swap the devices so one by one they all work properly. but the last i connect gives me this error. Please help

Chowhound
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