Registration failed, unregister scannerId = 0

[exp131]

I'm trying to run the example app on my Galaxy S9+, but every time I press Scan button I got this: D/BluetoothAdapter(25359): STATE_ON D/BluetoothLeScanner(25359): Start Scan with callback D/BluetoothLeScanner(25359): onScannerRegistered() - status=133 scannerId=0 mScannerId=0 D/BluetoothLeScanner(25359): Registration failed, unregister scannerId = 0 D/BluetoothLeScanner(25359): Scan failed, reason: app registration failed D/FlutterBluePlugin(25359): mDevices size: 0 D/BluetoothAdapter(25359): STATE_ON D/BluetoothLeScanner(25359): could not find callback wrapper D/FlutterBluePlugin(25359): mDevices size: 0 What can it be?

[DeedeeSRB]

I got the same problem and the way I fixed it was to restart my phone. This problem also caused my smartwatch not to connect properly. I found this (https://stackoverflow.com/questions/39325864/android-ble-scan-failed-reason-app-registration-failed-for-uuid) which explains how to scan/stop scan/connect/disconnect properly. I guess I was doing something wrong with that and that's why I got the error.

[Berkant35]

Change package to flutter blue plus https://pub.dev/packages/flutter_blue_plus

[alholan]

I have encountered same error with https://pub.dev/packages/flutter_blue_plus : D/BluetoothLeScanner( 9732): Registration failed, unregister scannerId = 0 D/BluetoothLeScanner( 9732): Scan failed, reason: app registration failed

I restarted the phone and it works!