Bluetooth rfcomm connection failure it throws exception saying deniedbysystem

Question

I am trying to make Bluetooth rfcomm connection with my mobile device but when i run this code it give me exception System.UnauthorizedAccessException: 'Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))'_

 Guid HFP_Id = new Guid("0000111f-0000-1000-8000-00805f9b34fb");
DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(BluetoothDevice.GetDeviceSelectorFromPairingState(true));

            var d2 = await DeviceInformation.FindAllAsync(

            RfcommDeviceService.GetDeviceSelector(

                RfcommServiceId.FromUuid(HFP_Id)));

            if(d2.Count>0)

            {

                BTDevice.Text = d2[0].Name.ToString();

                var desired_service = await RfcommDeviceService.FromIdAsync(d2[0].Id);  //giving null

                BlutooDevice = await BluetoothDevice.FromIdAsync(d2[0].Id);

                var result = await BlutooDevice.GetRfcommServicesForIdAsync(RfcommServiceId.FromUuid(HFP_Id));

                var desired_service2 = result.Services[0];

                BTSocket = new StreamSocket();

                await BTSocket.ConnectAsync(

                        desired_service2.ConnectionHostName,desired_service2.ConnectionServiceName,SocketProtectionLevel.BluetoothEncryptionAllowNullAuthentication

                        );

                BTDevice.Text = "connected";

                

            }

Capabilities

<Capabilities>
	  <DeviceCapability Name="bluetooth.rfcomm">
		  <Device Id="any">
			  <Function Type="serviceId:0000111f-0000-1000-8000-00805f9b34fb"/>
			  <Function Type="name:HandsfreeGateway"/>
		  </Device>
	  </DeviceCapability>
    <DeviceCapability Name="bluetooth" />
  </Capabilities>