Android ADB devices unauthorized

Question

Configuration:

• Windows 8.1
• ADB version: 1.0.32
• Smartphone: Oneplus One

Problem

I installed the Samsung drivers as it is said to do. When I run the ADB devices command, it said unauthorized.

Already tried:

1. I've done everything that'd been said on this post: https://stackoverflow.com/a/25546300/1848376

   But the problem is that I don't get a prompt on the phone to tell me I must accept the connection.

2. When I run the command adb shell, here is the answer:

   error: device unauthorized.
   This adbd's $ADB_VENDOR_KEYS is not set; try 'adb kill-server' if that seems wrong.
   Otherwise check for a confirmation dialog on your device.
   

I did "adb kill-server", but it didn't change anything. Why?

Answer 1

1. Try Revoke USB DEBUGGING Authorization.
2. Enable USB debugging again.

It worked.