ACF Error

I recommend asking at https://www.ads-software.com/plugins/advanced-custom-fields/#new-post so the plugin’s developers and support community can help you with this.

Hello @ovalhead ,
The Error message “ACF was unable to perform validation due to an invalid security nonce being provided” is a typically occurs due to security nonce validation issue in WordPress.
Here are steps to troubleshoot and resolve this issue:

1. Clear Browser Cache.
2. Check Theme or Plugin Conflict.
3. Increase PHP Memory Limit.
   Copy code, and mention into the wp-config.php
   define(‘WP_MEMORY_LIMIT’, ‘256M’);
4. Update ACF and WordPress.
5. Check for Nonce Expiry.
6. Fix Nonce Verification Code,If you’ve customized any part of the ACF or WordPress backend, ensure the nonce verification code is correct. It should look like this:
   wp_nonce_field( ‘acf_save_post’, ‘acf_nonce’ );
7. Disable Object Caching.
8. Check for Javascript Errors.
   If these steps don’t resolve the issue, let me know and we can investigate further!

I was able to resolve this issue by removing the following code from functions.php, which was being used to try and show WP’s default custom fields interface even with ACF installed.

// show default custom fields, even with ACF add_filter( 'acf/settings/remove_wp_meta_box', '__return_false' );