Fatal error: Uncaught Error: Class "Illuminate\Database\Eloquent\Relations\BelongsToMany" not found in C:\WebServer\htdocs\bookshelf\vendor\laravel\framework\src\Illuminate\Database\Eloquent\Relations\MorphToMany.php:18 Stack trace: #0 {main} thrown in C:\WebServer\htdocs\bookshelf\vendor\laravel\framework\src\Illuminate\Database\Eloquent\Relations\MorphToMany.php on line 18