I'm being the follower with "This happens to my computer, too." I can't unplug the device using too much power, because I haven't plugged anything in. This started happening after the "El Capitan" upgrade.
FWIW, the right-side USB port on my "Retina 15-inch, Early 2013" stopped working before the upgrade, and still doesn't work. I tried the two reset steps, didn't help.