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Starting with Android 4.2.x, Google requires that devices authorize before an adb debugging connection is allowed.
Typically, this isn't an issue for Amazon Fire TV devices. If it does occur, try toggling USB Debugging in Developer Options and deleting/renaming the .android/adbkey and .android/adbkey.pub files in your $HOME directory. This should force your device to reauthorize.
For Android TV devices like the Nvidia Shield:
Turn on Developer Options in Settings.
Scroll down to the bottom, or for Android TV to the right of the first row, and select About tablet.
Scroll to the bottom of About tablet, to find Build number, and tap the Build number area repeatedly, until the device says that the developer options have been unlocked.
If you get a message that reads, "No need, you are already a developer," then this step has already been done.
Open Developer Options and enable USB Debugging and Network Debugging.
Connect your device via USB.
Enable the "always allow from this computer" checkbox in the dialog that should pop up.
If the authorization dialog does not appear, try deleting/renaming the .android/adbkey and .android/adbkey.pub files in your $HOME directory. This should force your device to reauthorize. If you have questions or comments, please email firstname.lastname@example.org. adbLink produces a log file, adblink.log, with each run. Include it in your email or post if you're having problems.
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