Fatal error: Uncaught Error: Class "think\File" not found in C:\xampp\htdocs\HeTongSite\vendor\topthink\framework\src\think\file\UploadedFile.php:18 Stack trace: #0 {main} thrown in C:\xampp\htdocs\HeTongSite\vendor\topthink\framework\src\think\file\UploadedFile.php on line 18