Fatal error: Uncaught TypeError: usort(): Argument #1 ($array) must be of type array, null given in /var/www/html/controllers/controller.php:42 Stack trace: #0 /var/www/html/controllers/controller.php(42): usort() #1 /var/www/html/controllers/product.php(87): Controller->load() #2 /var/www/html/index.php(45): ProductController->load() #3 {main} thrown in /var/www/html/controllers/controller.php on line 42