array_key_exists(): The first argument should be either a string or an integer. Problem with updating account details

Using laravel to create a website for readers and authors to post and discuss books. Working on a My accounts page where users can update their details. Was working until i added the about you section, now everything updates ok to the database but brings this error. I will add the respected code snippets, if you could help me out would be great.

use Auth;
use Session;
class ProfileController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        return view('admin.users.profile')->with('user', Auth::user());
    }
public function update(Request $request)
    {
        $this->validate($request, ['name' => 'required','email' => 'required|email']);
        $user = Auth::user();

        $user->name = $request->name;
        $user->email = $request->email;
        $user->about = $request->about;

        $user->save();

        if($request->has('password' == 'confirmPassword'))
        {
            $user->password = bcrypt($request->password);
            $user->save();
        }

        Session::flash('success', 'Profile updated.');

        return redirect()->back();
    }

<div class="form-group">
                <label for="about">About You</label>
                <textarea name="about" value="" id="about" cols="6" rows="6" class="form-control"></textarea>
            </div>
            <div class="form-group">
                <div class="text-centre">
                    <button class="btn btn-success" type="submit">
                        Save Changes
                    </button>

class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password', 'about' 
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];

class UsersController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        $user = users::all();
        $name = 'name';
        $email = 'email';
        $password = 'password';
        $about = 'about';
        return view('admin.users.index');
    }

via Chebli Mohamed