Fatal error: Uncaught Error: Class "think\Model" not found in C:\xampp\htdocs\CnVideosSite\vendor\topthink\think-orm\src\model\Pivot.php:21 Stack trace: #0 {main} thrown in C:\xampp\htdocs\CnVideosSite\vendor\topthink\think-orm\src\model\Pivot.php on line 21