Fatal error: Uncaught Error: Class 'think\Loader' not found in D:\wwwroot\www.jiadaoxueche.com\core\base.php:68 Stack trace: #0 D:\wwwroot\www.jiadaoxueche.com\core\start.php(16): require() #1 D:\wwwroot\www.jiadaoxueche.com\index.php(55): require('D:\\wwwroot\\www....') #2 {main} thrown in D:\wwwroot\www.jiadaoxueche.com\core\base.php on line 68