Note: ADB over WiFi is not supported in browser-only mode. Browsers cannot make direct TCP connections. Please use USB connection.

Another process is holding the USB interface, so the browser cannot claim it. Try these in order:

1. Close other ADB clients. If a terminal has adb running, kill it: adb kill-server
2. Close other browser tabs that are connected to the same device (Chrome only lets one tab hold the interface).
3. Close Android Studio / scrcpy / Vysor or any other tool that talks to the device over USB.
4. Unplug and replug the device, accept the USB-debugging prompt again, then click Connect.