Android 4.2.2 USB debugging "Always allow from this computer" option result in target unknown for device?

Question

I am having problem connecting my 4.2.2 android device with PC after I select "Always allow from this computer".

I have selected "Always allow from this computer" in 4.2.2 USB debugging and it works fine the first time but when I tried other time my devices always appear offline. I have tried with another device that is also 4.2.2 and the USB debugging popup and when I click ok (without selecting "Always allow from this computer") with device list became online.

I have tried the following method and it didn't work

• adb kill-server/ adb start-server/ and adb devices
• install new eclipse, android SDK, and ADT
• Plug and unplug my device thousand times
• try repeating steps from this link

Are there anyway to get rid of "Always allow from this computer" once I selected?

Solution 1

As described in this issue, this can happen if you run adb for the first time as root. It creates a key file on your computer owned by the root user, so your normal user account can't read or overwrite it.

To check if this is the case:

$ ls -l ~/.android/adbkey
-rw------- 1 root root 1708 Nov 13  2012 .android/adbkey
             ^ notice root here

To fix it:

$ sudo chown $USER: ~/.android/adbkey
$ ls -l ~/.android/adbkey
$ -rw------- 1 thomas thomas 1708 Nov 13  2012 /home/thomas/.android/adbkey
               ^ now shows your username and primary group

Finally, restart the adb server:

$ adb kill-server
$ adb start-server

Solution 2

Revoke USB Debugging authorization from Settings in Android device and restart adb server on PC. The dialog will appear again while connecting to PC.

for restarting ADB server

$ adb kill-server

$ adb start-server

Solution 3

1. In your device: Go to settings
2. Select developer options
3. Tap Revoke USB debugging authorization
4. Press Ok

Solution 4

When i connected my Galaxy S3 running a 4.2.2 AOSP build, im presented with the pop up to allow debugging with the computer on my device.

On Eclipse - you see the following until you click "OK" on your device to allow USB debugging with the machine. It should change to the Target Android OS after you Press OK.

In your case - Your device seems to keep going offline after the first time you press the debugging dialog.

• Try another 4.2 Android device
• Do you have a custom ROM on your device?
• Is your ROM AOSP?

Solution 5

I've had nothing but problems with this since upgrading to 4.2.2 (Google Nexus 10).

In device chooser I keep getting 'Unknown' as the target.

The only thing that works for me is to:

• Disconnect the device from the PC/Laptop
• Close Eclipse.
• Go into settings on your device and disable USB Debugging
• Re-enable USB debugging
• Re-Connect device to PC/Laptop
• Wait until windows detects the device and display the autoplay window.
• Close this window
• Re-open Eclipse

It's a bit of a pain, but it works for me!

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