Фатальная ошибка имени класса загрузчика PHP Dropbox

Я пытался внедрить PHP Dropbox Uploader на мой сайт (находится здесь: https://github.com/jakajancar/DropboxUploader) и я не могу заставить его работать правильно. Ошибка, которую я продолжаю получать:

Fatal error: Class name must be a valid object or a string in [document name] on line 51.

Сначала мой php-код на моей странице загрузки:

<?php
if ($_POST) {
require 'DropboxUploader.php';

try {
if ($_FILES['file']['error'] !== UPLOAD_ERR_OK)
throw new Exception('File was not successfully uploaded from your computer.');

if ($_FILES['file']['name'] === "")
throw new Exception('File name not supplied by the browser.');

// Upload
$uploader = new DropboxUploader($_POST['[email protected]'], $_POST['mypassword']);
$uploader->upload($_FILES['file']['tmp_name'], $_POST['NEWFORMS, INC'], $_FILES['file']['name']);

echo '<span style="color: green">File successfully uploaded to your Dropbox!</span>';
} catch (Exception $e) {
// Handle Upload Exceptions
$label = ($e->getCode() & $uploader::FLAG_DROPBOX_GENERIC) ? 'DropboxUploader' : 'Exception';
$error = sprintf("[%s] #%d %s", $label, $e->getCode(), $e->getMessage());

echo '<span style="color: red">Error: ' . htmlspecialchars($error) . '</span>';
}
}
?>

И HTML со страницы загрузки:

<div class="cell-9">
<h1 class="block-head"> Upload Files to our Dropbox </h1>
<form method="POST" enctype="multipart/form-data">
<dl>
<dt><label for="email">Dropbox e-mail</label></dt>
<dd><input type="text" id="email" name="email"></dd>
<dt><label for="password">Dropbox password</label></dt>
<dd><input type="password" id="password" name="password"></dd>
<dt><label for="destination">Destination directory (optional)</label></dt>
<dd><input type="text" id="destination" name="destination"> e.g. "dir/subdirectory", will              be created if it doesn't exist</dd>
<dt><label for="file"></label>File</dt>
<dd><input type="file" id="file" name="file"></dd>
<dd><input type="submit" value="Upload the file to my Dropbox!"></dd>
</dl>
</form>
</div>

Вот PHP из моего PHP-файла DropboxUploader:

    <?php

final class DropboxUploader {
/**
* Certificate Authority Certificate source types
*/
const CACERT_SOURCE_SYSTEM = 0;
const CACERT_SOURCE_FILE   = 1;
const CACERT_SOURCE_DIR    = 2;
/**
* Dropbox configuration
*/
const DROPBOX_UPLOAD_LIMIT_IN_BYTES = 314572800;
const HTTPS_DROPBOX_COM_HOME        = 'https://www.dropbox.com/home';
const HTTPS_DROPBOX_COM_LOGIN       = 'https://www.dropbox.com/login';
const HTTPS_DROPBOX_COM_LOGINACTION = 'https://www.dropbox.com/ajax_login';
const HTTPS_DROPBOX_COM_UPLOAD      = 'https://dl-web.dropbox.com/upload';
const HTTPS_DROPBOX_COM_LOGOUT      = 'https://www.dropbox.com/logout';
/**
* DropboxUploader Error Flags and Codes
*/
const FLAG_DROPBOX_GENERIC        = 0x10000000;
const FLAG_LOCAL_FILE_IO          = 0x10010000;
const CODE_FILE_READ_ERROR        = 0x10010101;
const CODE_TEMP_FILE_CREATE_ERROR = 0x10010102;
const CODE_TEMP_FILE_WRITE_ERROR  = 0x10010103;
const FLAG_PARAMETER_INVALID      = 0x10020000;
const CODE_PARAMETER_TYPE_ERROR   = 0x10020101;
const CODE_FILESIZE_TOO_LARGE     = 0x10020201;
const FLAG_REMOTE                 = 0x10040000;
const CODE_CURL_ERROR             = 0x10040101;
const CODE_LOGIN_ERROR            = 0x10040201;
const CODE_UPLOAD_ERROR           = 0x10040401;
const CODE_SCRAPING_FORM          = 0x10040801;
const CODE_SCRAPING_LOGIN         = 0x10040802;
const CODE_CURL_EXTENSION_MISSING = 0x10080101;
private $email;
private $password;
private $caCertSourceType = self::CACERT_SOURCE_SYSTEM;
private $caCertSource;
private $loggedIn = FALSE;
private $cookies = array();

/**
* Constructor
*
* @param string $email
* @param string $password
* @throws Exception
*/
public function __construct($email, $password) {
// Check requirements
if (!extension_loaded('curl'))
throw new Exception('DropboxUploader requires the cURL extension.', self::CODE_CURL_EXTENSION_MISSING);

if (empty($email) || empty($password)) {
throw new Exception((empty($email) ? 'Email' : 'Password') . ' must not be empty.', self::CODE_PARAMETER_TYPE_ERROR);
}

$this->email    = $email;
$this->password = $password;
}

public function setCaCertificateDir($dir) {
$this->caCertSourceType = self::CACERT_SOURCE_DIR;
$this->caCertSource     = $dir;
}

public function setCaCertificateFile($file) {
$this->caCertSourceType = self::CACERT_SOURCE_FILE;
$this->caCertSource     = $file;
}

public function upload($source, $remoteDir = '/', $remoteName = NULL) {
if (!is_file($source) or !is_readable($source))
throw new Exception("File '$source' does not exist or is not readable.", self::CODE_FILE_READ_ERROR);

$filesize = filesize($source);
if ($filesize < 0 or $filesize > self::DROPBOX_UPLOAD_LIMIT_IN_BYTES) {
throw new Exception("File '$source' too large ($filesize bytes).", self::CODE_FILESIZE_TOO_LARGE);
}

if (!is_string($remoteDir))
throw new Exception("Remote directory must be a string, is " . gettype($remoteDir) . " instead.", self::CODE_PARAMETER_TYPE_ERROR);

if (is_null($remoteName)) {
# intentionally left blank
} else if (!is_string($remoteName)) {
throw new Exception("Remote filename must be a string, is " . gettype($remoteDir) . " instead.", self::CODE_PARAMETER_TYPE_ERROR);
}

if (!$this->loggedIn)
$this->login();

$data       = $this->request(self::HTTPS_DROPBOX_COM_HOME);
$file       = $this->curlFileCreate($source, $remoteName);
$token      = $this->extractFormValue($data, 't');
$subjectUid = $this->extractFormValue($data, '_subject_uid');

$postData = array(
'plain'        => 'yes',
'file'         => $file,
'dest'         => $remoteDir,
't'            => $token,
'_subject_uid' => $subjectUid,
'mtime_utc'    => filemtime($source),
);

$data     = $this->request(self::HTTPS_DROPBOX_COM_UPLOAD, $postData);
if (strpos($data, 'HTTP/1.1 302 FOUND') === FALSE)
throw new Exception('Upload failed!', self::CODE_UPLOAD_ERROR);
}

private function curlFileCreate($source, $remoteName) {
if (function_exists('curl_file_create')) {
return curl_file_create($source, NULL, $remoteName);
}

if ($remoteName !== NULL) {
$source .= ';filename=' . $remoteName;
}

return '@' . $source;
}

public function uploadString($string, $remoteName, $remoteDir = '/') {
$exception = NULL;

$file = tempnam(sys_get_temp_dir(), 'DBUploadString');
if (!is_file($file))
throw new Exception("Can not create temporary file.", self::CODE_TEMP_FILE_CREATE_ERROR);

$bytes = file_put_contents($file, $string);
if ($bytes === FALSE) {
unlink($file);
throw new Exception("Can not write to temporary file '$file'.", self::CODE_TEMP_FILE_WRITE_ERROR);
}

try {
$this->upload($file, $remoteDir, $remoteName);
} catch (Exception $exception) {
# intentionally left blank
}

unlink($file);

if ($exception)
throw $exception;
}

private function login() {
$data  = $this->request(self::HTTPS_DROPBOX_COM_LOGIN);
$token = $this->extractTokenFromLoginForm($data);

$postData = array(
'login_email'    => (string) $this->email,
'login_password' => (string) $this->password,
't'              => $token
);
$data     = $this->request(self::HTTPS_DROPBOX_COM_LOGINACTION, http_build_query($postData));

if (stripos($data, '{"status": "OK", "csrf_token": "') === FALSE)
throw new Exception('Login unsuccessful.', self::CODE_LOGIN_ERROR);

$this->loggedIn = TRUE;
}

private function logout() {
$data = $this->request(self::HTTPS_DROPBOX_COM_LOGOUT);

if (!empty($data) && strpos($data, 'HTTP/1.1 302 FOUND') !== FALSE) {
$this->loggedIn = FALSE;
}
}

private function request($url, $postData = NULL) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, (string) $url);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, TRUE);
switch ($this->caCertSourceType) {
case self::CACERT_SOURCE_FILE:
curl_setopt($ch, CURLOPT_CAINFO, (string) $this->caCertSource);
break;
case self::CACERT_SOURCE_DIR:
curl_setopt($ch, CURLOPT_CAPATH, (string) $this->caCertSource);
break;
}
curl_setopt($ch, CURLOPT_HEADER, TRUE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
if (NULL !== $postData) {
curl_setopt($ch, CURLOPT_POST, TRUE);
curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
}

// Send cookies
$rawCookies = array();
foreach ($this->cookies as $k => $v)
$rawCookies[] = "$k=$v";
$rawCookies = implode(';', $rawCookies);
curl_setopt($ch, CURLOPT_COOKIE, $rawCookies);

$data  = curl_exec($ch);
$error = sprintf('Curl error: (#%d) %s', curl_errno($ch), curl_error($ch));
curl_close($ch);

if ($data === FALSE) {
throw new Exception($error, self::CODE_CURL_ERROR);
}

// Store received cookies
preg_match_all('/Set-Cookie: ([^=]+)=(.*?);/i', $data, $matches, PREG_SET_ORDER);
foreach ($matches as $match)
$this->cookies[$match[1]] = $match[2];

return $data;
}

private function extractFormValue($html, $name) {
$action  = self::HTTPS_DROPBOX_COM_UPLOAD;
$pattern = sprintf(
'/<form [^>]*%s[^>]*>.*?(?:<input [^>]*name="%s" [^>]*value="(.*?)"[^>]*>).*?<\/form>/is'
, preg_quote($action, '/')
, preg_quote($name, '/')
);
if (!preg_match($pattern, $html, $matches))
throw new Exception(sprintf("Cannot extract '%s'! (form action is '%s')", $name, $action), self::CODE_SCRAPING_FORM);
return $matches[1];
}

private function extractTokenFromLoginForm($html) {
// , "TOKEN": "gCvxU6JVukrW0CUndRPruFvY",
if (!preg_match('#, "TOKEN": "([A-Za-z0-9_-]+)", #', $html, $matches))
throw new Exception('Cannot extract login CSRF token.', self::CODE_SCRAPING_LOGIN);
return $matches[1];
}

public function __destruct() {
if ($this->loggedIn) {
$this->logout();
}
}

}

Я удалил свою электронную почту и пароль по понятным причинам, но в моем собственном файле я их ввел. Любые идеи относительно того, что вызывает мою ошибку и как я могу это исправить?