如何在cakephp 3.0中解码数据库的json对象

I am trying to do a new database entry off of a http post request in cakephp 3. In cakephp 3 they are now using entities to manipulate the data. I have a rest api that uses json. I want to take that json data and put it in my database, here is what I am doing -

    public function add() {
    $user = $this->Users->newEntity();
    $user = $this->Users->patchEntity($user, $this->request->data);
    $array = $user->toArray();
    $this->Users->save($user);}

My json data that is being sent in http post -

{"userID":60,"firstname":"Sherbert60","lastname":"Dafflemore60","profilepic":"nada"}

The error I receive -

Error: Call to a member function errors() on array File /var/app/current/vendor/cakephp/cakephp/src/ORM/Table.php Line: 1356

Does anyone know what I am doing wrong? Thanks

EDIT -

Read in the docs that cakephp will automatically handle it if it is json, so I changed my code to -

    $user = $this->Users->newEntity($this->request->data);
    if ($this->Users->save($user)) {
        $message = 'Saved';
    } else {
        $message = 'Error';
    }

Now I get a 200 response with no entry into database. I can query the database with no problems.