Karik Select multiple Array_combine error

Hi, i use multiple kartik select dropdownlist.

My view

 echo $form->field($model, 'id_place')->widget(Select2::classname(), [

        'theme' => Select2::THEME_KRAJEE,

        'language' => 'pl',

        'options' => ['placeholder' => 'Select  place',





    ])->label("Miejsce:  max (5)"); ?>


    if ($model->load(Yii::$app->request->post())) {

            foreach ($_POST['Reservation']['id_place']  as $key=> $item) {

                $model->id_reservation = NULL;

                $model->create_at = date('Y-m-d H:i:s');

                $model->auth_key = Yii::$app->security->generateRandomString();


                $model->isNewRecord = true;



            return $this->redirect(['view', 'id' => $model->id_reservation]);


array_combine() expects parameter 1 to be array, integer given

I can add some items in foreach, but i can’t update single item? If I will remove multiple=>true i can update item but i can’t add a few items ?