Fail to connect to camera service cause null

Using Twilio , when receiving call always front camera fail to load.

Note : It works fine when calling.

Error Message : Unable to open camera Camera 1, Facing front, Orientation 270:Fail to connect to camera service cause null

Code

  cameraCapturer= CameraCapturerFactory.createCameraCapturer(this, CameraCapturer.CameraSource.CAMERA_SOURCE_FRONT_CAMERA, capturerErrorListener())

/*

* CameraCapture error listener */

 public CapturerErrorListener capturerErrorListener() {
    return new CapturerErrorListener() {
        @Override
        public void onError(CapturerException e) {

            Log.e(TAG, "Camera capturer error: " + e.getMessage()+" cause  "+e.getCause());

        }
    };
}

Copyright License：
Author:「Jithish P N」,Reproduced under the CC 4.0 BY-SA copyright license with link to original source & disclaimer.
Link to：https://stackoverflow.com/questions/38099012/fail-to-connect-to-camera-service-cause-null