Experiencing Issues with WordPress Menu Structure: Post-Submission Blank Page

Next time this happens, check both your browser console and the PHP error log for additional clues about what had gone wrong.

@bcworkz I did checked error log in home directory but nothing was there

It could be a plugin or your theme is interfering. Try switching to a default Twenty* theme and deactivating all plugins. You should now be able to submit your large menu structure if one was interfering. AFAIK there’s no arbitrary limit on the number of menu items in plain vanilla WP.

To isolate the specific module causing trouble, restore your usual theme and plugins, one at a time, testing after each. When the problem returns, the last activated is the cause. You could then take up the issue with its dedicated support channel to see if there’s a way to allow what you need.

@bcworkz I’ve attempted troubleshooting by disabling all plugins except for WooCommerce and using the Storefront theme, but the issue unfortunately persists.

Even well established themes and plugins can have undiscovered bugs that are only exposed in unusual situations like extremely large menus. To fully test, you really need to deactivate all plugins and activate a default theme.

If you’re reluctant to disable your storefront site for even a brief test, you can use the Health Check and Troubleshooting plugin to test. Its troubleshooting mode will deactivate all plugins and switch to a default theme for your view only. Other visitors will see you normal site. The troubleshooting admin bar item will let you restore your theme and plugins one at a time for further testing.

A blank screen strongly suggests some sort of PHP error. It is possible there is also an issue with your error logging. Try defining WP_DEBUG as true in wp-config.php. Then any error messages should be output directly on your screen.

Hi @bcworkz , I tried everything you mentioned but didn’t learn anything new, just same blank page and in dev console as always it says
POST https://ssfurnishings.com/wp-admin/nav-menus.php 402 (Payment Required)

But when I copied files & db to a test server, it seemed to fix the problem but I am unable to find the reason behind it to make it work on live server.

402 Payment Required? That’s a very unusual response! Especially with a plain vanilla WP installation. The issue lies within the server configuration, external to WP. Reinforced by your investigation with a test server. Success on a different server indicates something unusual about the live server.

Review the .htaccess file to see if there is any directive that could cause a 402 response. If you see nothing there, you’ll likely need to seek assistance from your host.