Creating default object from empty value laavel5.3

i'm just trying to do my update function in laravel 5.3 and then i got this erros" "ErrorException in gestionpersonnel.php line 96: Creating default object from empty value" and this is the function code :

    $id = $request->input('id');
    $personnel = personnels::find($id);
    $personnel->CIN =  Input::get('CIN ', 8);
    $personnel->nom  = $request->input('nom', 50);
    $personnel->prenom = $request->input('prenom', 50);
    $personnel->date = $request->input('date');
      $personnel->numtel = $request->input('numtel');
        $personnel->adress = $request->input('adress');
          $personnel->emai = $request->input('email');`
            $personnel->post = $request->input('post');

    $personnel->save();

    return redirect('/home')

and line numb 96 is : `$personnel->CIN = Input::get('CIN ', 8)

via Ennaoui Khouloud