It’s likely that the device is no longer authorized on ADB for whatever reason.
1. Check if authorized:
List of devices attached
4df798d76f98cf6d unauthorized
2. Revoke USB Debugging on phone
If the device is shown as unauthorized, go to the developer options on the phone and click “Revoke USB debugging authorization” (tested with JellyBean & Samsung GalaxyIII).
3. Restart ADB Server:
Then restarted adb server
adb kill-server
adb start-server
4. Reconnect the device
The device will ask if you are agree to connect the computer id.
You need to confirm it.
5. Now Check the device
It is now authorized!
adb devices
List of devices attached
4df798d76f98cf6d device
Ohhh finally I figured it out!
After removing Eclipse directory I installed it into another directory.
echo %ANDROID_SDK_HOME%
has displayed wrong path to sdk directory.
set ANDROID_SDK_HOME “E:adt-bundle-windows-x86_64-20140321sdk”
unplug device
adb kill-server
adb start-server
plug device
After these steps, I was able to see confirmation dialog with RSA fingerprint on my phone 🙂