使用隐藏URL下载时，文件的格式未知

每次使用此代码并下载文件时，都会收到一个错误。我想这是因为文件的路径。

download.php文件位于/modules/中，包含在根目录（htdocs/project/）/中的index.php中。该文件位于/modules/download/file.zip 上

原因可能是什么？URL应该是系统路径吗？如果我不想使用系统路径怎么办？或者我的另一个问题是什么？

        $stmt = $this->GetDatabaseConnection()->prepare('SELECT * FROM download_files WHERE id=?');
        $stmt->bind_param('i', $_GET['file']);
        $stmt->execute();
        $stmt->store_result();
        $stmt->bind_result($id, $name, $desc, $filename, $size, $added, $clicks, $uclicks);
        $stmt->fetch();
        if($stmt->num_rows > 0) {
            $fakeFileName= $name . '.zip';
            $realFileName = $filename;
            $file = "download/".$realFileName;
            $fp = fopen($file, 'rb');
            header("Content-Type: application/octet-stream");
            header("Content-Transfer-Encoding: Binary");
            header("Content-Disposition: attachment; filename=$fakeFileName");
            header("Content-Length: " . filesize($file));
            fpassthru($fp);
            exit;
        }
        $stmt->free_result();
        $stmt->close();

错误：

<b>Warning</b>:  fopen(download/6694488-PHPUploadFile.zip): failed to open stream: No such file or directory in <b>C:'xampp'htdocs'project'modules'download.inc.php</b> on line <b>27</b><br />
<br />
<b>Warning</b>:  filesize(): stat failed for download/6694488-PHPUploadFile.zip in <b>C:'xampp'htdocs'project'modules'download.inc.php</b> on line <b>31</b><br />
<br />
<b>Warning</b>:  fpassthru() expects parameter 1 to be resource, boolean given in <b>C:'xampp'htdocs'project'modules'download.inc.php</b> on line <b>32</b><br />