think5 服务器复制到本地服务器， 前台显示正常功能正常 后台显示白屏

<?php

// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2016 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
// [ 后台入口文件 ]
// 使用此文件可以达到隐藏admin模块的效果
// 建议将admin.php改成其它任意的文件名，同时修改config.php中的'deny_module_list',把admin模块也添加进去
// 定义应用目录
define('APP_PATH', __DIR__ . '/../application/');

// 判断是否安装FastAdmin
if (!is_file(APP_PATH . 'admin/command/Install/install.lock'))
{
    header("location:./install.php");
    exit;
}

// 加载框架引导文件
require __DIR__ . '/../thinkphp/base.php';

// 绑定到admin模块
\think\Route::bind('admin');

// 关闭路由
\think\App::route(false);

// 设置根url
\think\Url::root('');

// 执行应用
\think\App::run()->send();

base.php 的

<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2018 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

define('THINK_VERSION', '5.0.24');
define('THINK_START_TIME', microtime(true));
define('THINK_START_MEM', memory_get_usage());
define('EXT', '.php');
define('DS', DIRECTORY_SEPARATOR);
defined('THINK_PATH') or define('THINK_PATH', __DIR__ . DS);
define('LIB_PATH', THINK_PATH . 'library' . DS);
define('CORE_PATH', LIB_PATH . 'think' . DS);
define('TRAIT_PATH', LIB_PATH . 'traits' . DS);
defined('APP_PATH') or define('APP_PATH', dirname($_SERVER['SCRIPT_FILENAME']) . DS);
defined('ROOT_PATH') or define('ROOT_PATH', dirname(realpath(APP_PATH)) . DS);
defined('EXTEND_PATH') or define('EXTEND_PATH', ROOT_PATH . 'extend' . DS);
defined('VENDOR_PATH') or define('VENDOR_PATH', ROOT_PATH . 'vendor' . DS);
defined('RUNTIME_PATH') or define('RUNTIME_PATH', ROOT_PATH . 'runtime' . DS);
defined('LOG_PATH') or define('LOG_PATH', RUNTIME_PATH . 'log' . DS);
defined('CACHE_PATH') or define('CACHE_PATH', RUNTIME_PATH . 'cache' . DS);
defined('TEMP_PATH') or define('TEMP_PATH', RUNTIME_PATH . 'temp' . DS);
defined('CONF_PATH') or define('CONF_PATH', APP_PATH); // 配置文件目录
defined('CONF_EXT') or define('CONF_EXT', EXT); // 配置文件后缀
defined('ENV_PREFIX') or define('ENV_PREFIX', 'PHP_'); // 环境变量的配置前缀

// 环境常量
define('IS_CGI', (0 === strpos(PHP_SAPI, 'cgi') || false !== strpos(PHP_SAPI, 'fcgi')) ? 1 : 0);
define('IS_CLI', PHP_SAPI == 'cli' ? true : false);
define('IS_WIN', strpos(PHP_OS, 'WIN') !== false);

// 载入Loader类
require CORE_PATH . 'Loader.php';

// 加载环境变量配置文件
if (is_file(ROOT_PATH . '.env')) {
    $env = parse_ini_file(ROOT_PATH . '.env', true);

    foreach ($env as $key => $val) {
        $name = ENV_PREFIX . strtoupper($key);

        if (is_array($val)) {
            foreach ($val as $k => $v) {
                $item = $name . '_' . strtoupper($k);
                putenv("$item=$v");
            }
        } else {
            putenv("$name=$val");
        }
    }
}


if (!defined('_PHP_FILE_')) {
    if (IS_CGI) {
        //CGI/FASTCGI模式下
        $_temp = explode('.php', $_SERVER['PHP_SELF']);
        define('_PHP_FILE_', rtrim(str_replace($_SERVER['HTTP_HOST'], '', $_temp[0] . '.php'), '/'));
    } else {
        define('_PHP_FILE_', rtrim($_SERVER['SCRIPT_NAME'], '/'));
    }
}
if (!defined('__ROOT__')) {
    $_root = rtrim(dirname(_PHP_FILE_), '/');
    $_root = $_root;
    define('__ROOT__', (('/' == $_root || '\\' == $_root) ? '' : $_root));
}
// 注册自动加载
\think\Loader::register();

// 注册错误和异常处理机制
\think\Error::register();

// 加载惯例配置文件
\think\Config::set(include THINK_PATH . 'convention' . EXT);

https://blog.csdn.net/shueiyuan1983/article/details/51768283