Resolving ADB Device Unauthorized Error in Android Studio

Background of the Issue

In Android development, Android Debug Bridge (ADB) is a crucial tool for connecting devices to computers for debugging. However, developers often encounter errors where logs show device unauthorized. Please check the confirmation dialog on your device., preventing access to application logcat output and affecting debugging efficiency. This error may be accompanied by other issues like device offline or AdbCommandRejectedException.

Error Cause Analysis

The "device unauthorized" error primarily occurs because the device is not properly authorized for the computer. When connecting for the first time, the device displays a confirmation dialog requesting permission for USB debugging. If this dialog is missed or authorization is denied, ADB cannot communicate. To prevent this, one can select "Revoke USB debugging authorizations" in the developer options to reset the process. Additionally, online articles mention the importance of RSA encryption keys; during connection, if the RSA key authorization is not accepted, the device may record a rejection state, requiring a device restart or deletion of existing sdbkey files.

Solution Steps

Based on the best answer, follow these detailed steps:

1. Change USB Mode: On the device, switch the USB mode from the current setting to another mode (e.g., Media Mode), then reconnect. This may trigger the confirmation dialog; ensure to click "Allow."

2. Revoke USB Debugging Authorization: In the device's developer options, find and select "Revoke USB debugging authorizations." Then, reconnect the device, monitor for the dialog, and click accept.

3. Set Environment Variables: If the above methods fail, check and reset the ANDROID_SDK_HOME environment variable. Run the following command in the command line:

   setx ANDROID_SDK_HOME "C:\Path\To\Android\Sdk"

   Or set it manually in the environment variables window.

4. Restart ADB Server: In the command line, run these commands:

   adb kill-server
   adb start-server

   Then, unplug the device (disconnect and reconnect), and check if the logs return to normal.

Supplementary Knowledge Points

Referencing online articles, similar issues appear on Tizen devices (e.g., Samsung Galaxy Watch). Key points include:

• RSA Key Authorization: During connection, the device shows an RSA encryption key confirmation; only after acceptance can secure communication proceed. If rejected, it may require a device restart or generating new keys by deleting files like sdbkey.
• Developer Options: Ensure that USB debugging and related debugging functions are enabled on the device.
• Certificate Management: For Samsung devices, specific Samsung certificates may be required instead of generic Tizen certificates. This involves installing extensions in Tizen Studio's Package Manager and generating certificates.
• Language Settings: In some cases, if the device uses a right-to-left language, it might cause errors in IP address input; switching the system language to English and retrying can resolve this.

Conclusion

Resolving ADB device unauthorized errors requires a comprehensive approach considering device settings, ADB configuration, and certificate management. By executing the above steps, most situations can restore debugging functionality. It is advisable to promptly respond to confirmation dialogs when connecting new devices and maintain proper environment variables and ADB server status. Moreover, understanding RSA keys and developer options helps prevent similar issues in the future.