Validation message is not shown about recaptcha HOT 2 OPEN

@if(count($errors->all()) > 0)
  <div class="alert alert-danger" role="alert"> <p><b>Attenzione!</b></p>
    <ul>
      @foreach($errors->all() as $error)
        <li>{{ $error }}</li>
      @endforeach
    </ul>
  </div>
@endif

                        <div class="form-group">
                            <div class="col-md-6 col-md-offset-4">{!! Recaptcha::render() !!}
                             @if ($errors->has('g-recaptcha-response'))
                                 <span class="help-block">
                                     <strong>{{ $errors->first('g-recaptcha-response') }}</strong>
                                 </span>
                             @endif
                            </div>
                        </div>