Undefined property: stdclass::$xfile

Tolong pencerahanya mas gan saya masih nubie jika error begini gimana mas gan...?

Undefined property: stdClass::$xfile ....on line 43
unlink(assets/uploads/dokumen/internal/): No such file or directory in ....on line 35

<?php
require_once('../config/koneksi.php');
require_once('../models/database.php');
include "../models/m_internal.php";
$connection = new Database($host, $user, $pass, $database);
$int = new Internal($connection);

$id = $_POST['id'];
$nomor = $connection->conn->real_escape_string($_POST['nomor']);
$kategori = $connection->conn->real_escape_string($_POST['kategori']);
$departemen = $connection->conn->real_escape_string($_POST['departemen']);
$revisi = $connection->conn->real_escape_string($_POST['revisi']);
$tanggal = $connection->conn->real_escape_string($_POST['tanggal']);
$status = $connection->conn->real_escape_string($_POST['status']);
$nama = $connection->conn->real_escape_string($_POST['nama']);

$objek = $_FILES['xfile']['name'];
$extensi = explode(".", $_FILES['xfile']['name']);
$xfile = "internal-".round(microtime(true)).".".end($extensi);
$sumber = $_FILES['xfile']['tmp_name'];

if($objek == '') {
    $int->edit("UPDATE tb_internal SET
    nomor_dokumen = '$nomor',
    kategori_dokumen = '$kategori',
    departemen_dokumen = '$departemen',
    revisi_dokumen = '$revisi',
    tanggal_revisi = '$tanggal',
    status_dokumen = '$status',
    nama_dokumen = '$nama' WHERE id = '$id'");

    echo "<script>window.location='?page=dokumen-internal';</script>";
} else {
    $file_lama = $int->tampil($id)->fetch_object()->xfile;
    unlink("../assets/uploads/dokumen/internal/".$file_lama);

    $upload = move_uploaded_file($sumber, "../assets/uploads/dokumen/internal/".$xfile);
    if($upload) {
        $int->edit("UPDATE tb_internal SET
        nomor_dokumen = '$nomor',
        kategori_dokumen = '$kategori',
        departemen_dokumen = '$departemen',
        revisi_dokumen = '$revisi',
        tanggal_revisi = '$tanggal',
        status_dokumen = '$status',
        nama_dokumen = '$nama',
        file_dokumen = '$xfile' WHERE id = '$id'");

        echo "<script>window.location='?page=dokumen-internal';</script>";
    } else {
        echo "<script>alert('Upload File Gagal!')</script>";
    }
}
?>

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