Warning: Undefined array key 6 in C:\xampp\htdocs\ECWCguest\GuestNews.php on line 53

Fatal error: Uncaught TypeError: in_array(): Argument #2 ($haystack) must be of type array, null given in C:\xampp\htdocs\ECWCguest\GuestNews.php:53 Stack trace: #0 C:\xampp\htdocs\ECWCguest\GuestNews.php(53): in_array(0, NULL) #1 {main} thrown in C:\xampp\htdocs\ECWCguest\GuestNews.php on line 53