未找到类“SimpleXMLElement”

我正在尝试在我的php7 laravel项目中使用数字海洋空间。代码非常简单，只需加载文件并将其复制到目录中即可。一切在我的本地计算机上工作正常，但在我的数字海洋服务器上失败，出现此错误

未找到类“SimpleXMLElement”

即使在数字海洋服务器上，如果我使用tinker来运行相同的存储命令，它也可以正常工作。可能是什么问题？

我的回报get_loaded_extensions（）get_loaded_extensions()

[
     "Core",
     "date",
     "libxml",
     "openssl",
     "pcre",
     "zlib",
     "filter",
     "hash",
     "pcntl",
     "Reflection",
     "SPL",
     "session",
     "standard",
     "mysqlnd",
     "PDO",
     "xml",
     "apcu",
     "calendar",
     "ctype",
     "curl",
     "dom",
     "mbstring",
     "fileinfo",
     "ftp",
     "gd",
     "gettext",
     "iconv",
     "json",
     "exif",
     "mysqli",
     "pdo_mysql",
     "Phar",
     "posix",
     "readline",
     "shmop",
     "SimpleXML",
     "sockets",
     "sysvmsg",
     "sysvsem",
     "sysvshm",
     "tokenizer",
     "wddx",
     "xmlreader",
     "xmlrpc",
     "xmlwriter",
     "xsl",
     "zip",
     "Zend OPcache",
   ]

所以它看起来像xml和simplexml被安装。如链接所示，应安装。我需要单独安装某些东西吗？php-xmlphp-simplexml

另外，我的文件上传代码看起来像这样

public function uploadNew($file, $title, User $user)
    {
        if (!File::directoryExists($user->username)) {
            Storage::makeDirectory($user->username);
        }
        $completeFileName = $user->username.'/'.$title.time();
        Storage::put($completeFileName, file_get_contents($file), 'public');
        $this->url = File::baseUrl().$completeFileName;
        $this->title = $title;
        $this->user_id = $user->id;
        $this->save();
        return $this;
    }

    public static function baseUrl()
    {
        return 'https://'.env('DO_SPACES_BUCKET').'.nyc3.digitaloceanspaces.com/';
    }

    public static function directoryExists($directory)
    {
        $existingDirs = Storage::directories();
        return in_array($directory, $existingDirs);
    }

添加异常的堆栈跟踪：

(1/1) FatalThrowableError
Class 'SimpleXMLElement' not found
in PayloadParserTrait.php (line 39)
at RestXmlParser->parseXml(object(Stream))
in RestXmlParser.php (line 33)
at RestXmlParser->payload(object(Response), object(StructureShape), array())
in AbstractRestParser.php (line 62)
at AbstractRestParser->__invoke(object(Command), object(Response))
in RetryableMalformedResponseParser.php (line 37)
at RetryableMalformedResponseParser->__invoke(object(Command), object(Response))
in AmbiguousSuccessParser.php (line 58)
at AmbiguousSuccessParser->__invoke(object(Command), object(Response))
in GetBucketLocationParser.php (line 30)
at GetBucketLocationParser->__invoke(object(Command), object(Response))
in WrappedHttpHandler.php (line 126)
at WrappedHttpHandler->parseResponse(object(Command), object(Request), object(Response), array())
in WrappedHttpHandler.php (line 93)
at WrappedHttpHandler->Aws\{closure}(object(Response))
in Promise.php (line 203)