Connecting Android Device Issue: adb Server Version (41) Doesn’t Match This Client (39); Killing
This error indicates a version mismatch between the Android Debug Bridge (adb) server running on your Windows computer and the adb client on your Android device. This can happen when you have multiple adb installations or when you have upgraded adb on one but not the other.
Understanding adb Server and Client
adb consists of two parts:
- Server: Runs on your computer and manages communication between your device and the computer.
- Client: Runs on your device and handles communication with the server.
Troubleshooting the Error
1. Restart adb Server
The simplest solution is to restart the adb server.
adb kill-server adb start-server
2. Check for Multiple adb Installations
If restarting the server doesn’t fix the issue, you might have multiple adb installations. To check this:
- Open the command prompt or PowerShell.
- Type
where adband press Enter.
If multiple locations are listed, you might need to remove or update the older versions.
3. Update adb
Ensure both your adb server and client are up-to-date. Here’s how to update them:
- Windows:
- If you’re using Android Studio, update it to the latest version.
- If you’re using the SDK tools directly, download and install the latest platform-tools package.
- Android Device:
- Go to Settings > About Phone > Build number.
- Tap 7 times on Build number to enable Developer Options.
- In Developer Options, enable USB Debugging.
4. Use a Different USB Cable
Try connecting your device using a different USB cable. A faulty cable can cause communication issues.
5. Verify Device Drivers
Ensure the proper device drivers are installed on your computer. If you’re using a new device, you might need to download and install the latest drivers.
Comparison of adb Versions
Here’s a table showing how to identify the adb version in the error message and understand the difference between server and client:
| Component | Version in Error Message | Meaning |
|---|---|---|
| adb server | 41 | The adb server on your computer is running version 41. |
| adb client | 39 | The adb client on your Android device is using version 39. |
Code Output
If you run the adb kill-server command, you should see a similar output:
* daemon not running. starting it now on port 5037 * * daemon started successfully *
Conclusion
The “adb server version mismatch” error can be resolved by following the troubleshooting steps outlined above. Ensure your adb server and client are updated to the latest versions, check for multiple installations, and verify device drivers. If the problem persists, consult relevant Android developer forums or community resources for additional assistance.