此问题可能是因为应用程序未被授予蓝牙权限。请确保在AndroidManifest.xml文件中添加以下权限:

如果您已经添加了这些权限但仍然无法启动蓝牙，您可能需要请求蓝牙权限。您可以使用以下代码示例请求权限:

private static final int REQUEST_BLUETOOTH_PERMISSIONS = 1;

private void checkBluetoothPermissions() {
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH) != PackageManager.PERMISSION_GRANTED ||
        ContextCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_ADMIN) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH, Manifest.permission.BLUETOOTH_ADMIN}, REQUEST_BLUETOOTH_PERMISSIONS);
    } else {
        startDiscovery();
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    if (requestCode == REQUEST_BLUETOOTH_PERMISSIONS) {
        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
            startDiscovery();
        }
    }
}

在您的Activity或Fragment中，调用checkBluetoothPermissions()方法来检查和请求蓝牙权限。如果权限已授予，则调用startDiscovery()开始蓝牙扫描。否则，用户将看到权限请求对话框。在用户授予权限后，扫描将开始。