I had this issue as well, Kingo root error.
However, I also had an error on Vroot stating USB debugging wasn't enabled though it was.
I guess persistence pays, and all the suggestions here, "10 min screen timeout, unknown sources checked etc".
After several phone reboots, pc reboots, re-attempts, and a re-re-download of the device USB drivers from Samsung, retried, finally worked with Vroot.
If you like it, support it! Support the DEVS, buy them a cup of coffee, send a paypal donation! Doooooo iiiiiiitttt!