Hello,
We apologize for the issue you are facing with your links after changing the permalink structure from plain to post name. When you change the permalink structure, it’s essential to ensure that any old URLs are redirected to the new ones to avoid broken links.
Since you mentioned that you turned on redirects and 404 errors but are not seeing any errors in the 404 monitor, it might be helpful to check if the redirection settings are correctly configured. You can set up redirections easily using Rank Math to ensure that users are directed to the correct URLs.
Here’s a helpful resource on how to set up redirections: Setting Up Redirections.
Additionally, if you continue to experience issues, we recommend replying to this ticket so a human agent from the Rank Math Support team can assist you further.
Thank you for raising this concern, and we hope to resolve it for you soon!
Hello,
Thank you for contacting Rank Math and bringing your concern to our attention. We’re sorry for any inconvenience this issue may have caused you.
This usually happens when you’re using a custom 404 page on your site.
For initial troubleshooting, please update this Rank Math file via FTP – /plugins/seo-by-rank-math/includes/modules/404-monitor/class-monitor.php
Then in line 53, change this:
$this->action( $this->get_hook(), 'capture_404' );
To this:
$this->action('template_redirect', 'capture_404' );
Once done, check again the 404 Monitor and see if it’s already logging them.
Please note that you may need to modify the code above each time you update Rank Math to detect your 404s.
Let us know how this goes.
Thank you.
actually i want to know what happen with 404 errors because when I set link like plain link such as: p?page_id=xxx it work very good but when I change into post name link that all are 404 errors, I really want to fix it
thank you
Hello,
Can you please confirm if deactivating our plugin will resolve the issue?
If so, 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/
We really look forward to helping you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.