Fatal error: Class 'think\Exception' not found in /www/wwwroot/www.sf123uu.com/thinkphp/library/think/exception/ErrorException.php on line 22

Fatal error: Uncaught Error: Class 'think\exception\ErrorException' not found in /www/wwwroot/www.sf123uu.com/thinkphp/library/think/Error.php:88 Stack trace: #0 [internal function]: think\Error::appShutdown() #1 {main} thrown in /www/wwwroot/www.sf123uu.com/thinkphp/library/think/Error.php on line 88