Having a huge/really large menu i get: Warning: Undefined array key in C:\xampp\htdocs\wp-includes\nav-menu-template.php

[mobilebsmith]

Would get the warnings below, and menu wouldn't show. Changing the code shown here (I left the original in, just commented out. fixed the issue.

------nav-menu-template.php------
	// Calculate the depth of each menu item with children.
	foreach ( $menu_items_with_children as $menu_item_key => &$menu_item_depth ) {
		//$menu_item_parent = $menu_items_tree[ $menu_item_key ];
		$menu_item_parent = isset($menu_items_tree[ $menu_item_key ]) ? $menu_items_tree[ $menu_item_key ] : null ;
		while ( $menu_item_parent ) {
			$menu_item_depth  = $menu_item_depth + 1;
			//$menu_item_parent = $menu_items_tree[ $menu_item_parent ];
			$menu_item_parent = isset($menu_items_tree[ $menu_item_parent ]) ? $menu_items_tree[ $menu_item_parent ] : null ;
		}
	}

--------- 

Warning: Undefined array key 21700 in C:\xampp\htdocs\wp-includes\nav-menu-template.php on line 211

Warning: Undefined array key 21700 in C:\xampp\htdocs\wp-includes\nav-menu-template.php on line 215

Warning: Undefined array key 21700 in C:\xampp\htdocs\wp-includes\nav-menu-template.php on line 215

[costdev]

Hi @mobilebsmith, welcome to Trac!

This was introduced in [54801]. Pinging @peterwilsoncc to take a look.

[peterwilsoncc]

Hi @mobilebsmith and welcome to trac!

This issue has been logged previously and is been tracked in issue #57122. I'll close this issue as a duplicate to keep conversation in one location.

The code is question is likely to be removed in 6.1.2 and replaced with another approach that will solve this issue.

Thanks for getting in touch.