adb.exe: no devices/emulators found

This error message indicates that the ADB (Android Debug Bridge) tool is unable to detect any connected devices or emulators. There are several possible reasons for this issue:

1. USB Connection: Make sure that your Android device is properly connected to your computer via USB cable. Check that the USB debugging option is enabled in the developer options on your Android device.

2. ADB Drivers: Ensure that the correct ADB drivers are installed on your computer for your Android device. You can check this by going to Device Manager on your computer, and then looking for your device under the "Android Device" category.

3. Restart ADB: Try restarting the ADB server by opening a command prompt and typing "adb kill-server" and then "adb start-server".

4. Update ADB: Check if there is any new version of ADB available for download. Install it if there is.

5. Firewall: Check if any firewall is blocking the ADB connection.

If none of these solutions work, try using a different USB cable or port. If the issue persists, there may be a hardware problem with your Android device or computer.