Read my older post adb not detecting the phone! to get some basic information about what adb is.
Now the problem came when I attached my phone to a freshly installed OS. This issue might only be specific to my OS. But I had to search the solution on the Internet when I faced it again. So thought of writing it myself this time.
So basically, it’s showing the device (9bb2ce65) but I can’t send any command (e.g. reboot) to my phone. Because it’s written there as “no permissions”. And it didn’t pop up any dialog box on my phone so that I could allow the permissions.
To add yourself to the plugdev group:
And kill the adb server.
Start it again, with:
Now the error is gone.