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

I got this as root when as a non-root user I was getting permissions errors trying to connect to custom recovery (Philz). so I killed adb server, copied the .android subdirectory of my user account into /root, chowned -R to root.root, and restarted adb server. I'm in!

Answer 2

I suppose you have enabled On-device Developer Options in your smartphone? If not you can take a look at the steps provided by Android, http://developer.android.com/tools/device.html#developer-device-options

Answer 3

In Android studio, Run menu > Run shows OFFLINE ... for the connected device.

Below is the procedure followed to solve it:

1. (Read the below note first) Delete the ~/.android/adbkey (or, rename to ~/.android/adbkey2, this is even better incase you want it back for some reason)
   Note: I happened to do this step, but it didn't solve the problem, after doing all the below steps it worked, so unsure if this step is required.

2. Run locate platform-tools/adb
   Note: use the path that comes from here in below commands

3. Kill adb server:
   sudo ~/Android/Sdk/platform-tools/adb kill-server

4. You will get a Allow accept.. message popup on your device. Accept it. This is important, which solves the problem.

5. Start adb server:
   sudo ~/Android/Sdk/platform-tools/adb start-server

6. In Android studio, do Run menu > Run again
   It will show something like Samsung ... (your phone manufacture name).
   Also installs the apk on device correctly this time without error.

Hope that helps.

Answer 4

Delete existing adbkeys

OR

Rename adbkeys

Best practise is to rename the keys because it provides backup.

cd ~/.Android

mv adbkey adbkey2

mv adbkey.pub adbkey.pub2

Next stop & start the server

cd ~/Android/Sdk/platform-tools

Locate the device /Android/Sdk/platform-tools$ ./adb devices

/Android/Sdk/platform-tools$ ./adb kill-server

/Android/Sdk/platform-tools$ ./adb start-server

Then, stop the emulator Open AVD manager, click on the down arrow, then click on wipe data

Restart the emulator. Then everything works fine :)

Answer 5

for anyone encountering this later this may also help. I encountered this exact issue trying to use adb from a user command prompt and the answers above did not help, but the problem went away with an "adb kill-server" when running in an administrator command prompt.

Answer 6

In sequence:

    adb kill-server

• in your DEVICE SETUP, go to developer-options end disable usb-debugging

• press REVOKE USB debugging authorizations, click OK

• enable usb-debugging

  adb start-server