Halaman locahost di browser kosong

kenapa saat di submit halaman di browser kosong, nggak muncul error juga. ini prosesnya

<?php
include('../../connect.php');

  $kategori = $_POST['kategori'];

  $folder = "category/";

  if(!empty($_FILES["filegbr"] ["tmp_name"])){
    $type_image = $_FILES["filegbr"]["tmp_name"];

    if($type_image == "image/jpeg" || $type_image == "image/jpg"){
      $lampiran = $folder . basename($_FILES['filegbr']['name']);

      if (move_uploaded_file($_FILES['filegbr']['tmp_name'], $lampiran)){

        $stmt = $db->prepare("INSERT INTO public.tb_categories(category, category_pict) VALUES ('$kategori', '$lampiran')");
        $stmt->execute();
      }echo "<script> window.location='blank.php'</script>";
    }
  }
?>