Most recent RankMath SEO update broke WordPress core code.

Hello,

Thank you for contacting us and sorry for any inconvenience that might have been caused due to that.

This issue could be caused by conflicting plugins/themes on your website. Kindly make sure you are using the latest version of all the plugins and themes, please update if not yet.

Here’s a guide for troubleshooting further if the issue persists:
https://rankmath.com/kb/check-plugin-conflicts/

You can also follow the steps in this video:
https://www.youtube.com/watch?v=FcIWRhcUP2c

Only the site admin would know and your users won’t be affected by this troubleshooting.

If the issue persists, then we might need to take a closer look at the settings. Please edit the first post on this ticket and include your WordPress & FTP logins in the designated Sensitive Data section.

Please do take a complete backup of your website before sharing the information with us.

It is completely secure and only our support staff has access to that section. If you want, you can use the below plugin to generate a temporary login URL to your website and share that with us instead:

https://wordpress.org/plugins/temporary-login-without-password/

You can use the above plugin in conjunction with the WP Security Audit Log to monitor what changes our staff might make on your website (if any):

https://wordpress.org/plugins/wp-security-audit-log/

Let us know how it goes. Looking forward to helping you.