Problem:
Why trying to access your Android device using ADB, you encounter the following error:
error: insufficient permissions for device
Solution:
The problem seem to be related to the one I described earlier.
For some reason, the ADB permission server has not been started as root.
So, kill the ADB server by executing (as the non-root-user you normally use):
adb kill-server
After that, you should restart the ADB USB service:
sudo adb usb
If that didn’t work, try running the
adb kill-server
command as root and repeat the adb usb
command.
If even that can’t get it to work, try rebooting.