Call to a member function saveAs() on a non-object

I am trying to run an application in Yii2 I tried to upload a user profile picture and it works greatly but the problem starts when I try to update the name file. It shows me an error like Call to a member function saveAs() on a non-object. I even tried to update without any changes… even that time also show me the same error… but error goes if I change the pic. this is my controller

public function actionUpdate($id)


$model = $this->findModel($id);

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

    // get the instance of uploaded file

    $imageName = $model->user_username;

    $model->file = UploadedFile::getInstance($model,'user_avatar');

    $model->file->saveAs( '/uploads/'.$imageName.'.'.$model->file->extension );

    //save the path in DB..

    $model->user_avatar = 'uploads/'.$imageName.'.'.$model->file->extension;


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

} else {

    return $this->render('update', [

        'model' => $model,




My link

  1. In view ,check your active form with

<?php $form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data']]) ?>