try.. catch..

public function update($id, Request $request) {
        $rules = array(
            'email'    => 'required|email', // make sure the email is an actual email
            'password' => 'required|alphaNum|min:3', // password can only be alphanumeric and has to be greater than 3 characters
            'konfirmasi_password' => 'required|same:password'
        );

        // run the validation rules on inputs from the form
        $validator = Validator::make($request->all(), $rules);

        if ($validator->fails()) {
            // Error
            $request->session()->flash('warning_ubah', 'Password tidak sama. Silahkan mencoba kembali. Terima kasih.');
            return redirect()->back();
        } else {
            try {
                $data = UsersModel::find($id);
                $input = $request->all();
                $data->fill($input)->save();
            } catch(Exception $e) {
                // Error
            }

            $request->session()->flash('success_ubah', 'Data berhasil diganti. Terima kasih.');
            return redirect()->back();
        }

    }