Undefined index: canonical

Hello,

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

Assuming you are using the latest version of all the plugins and the themes (please update if not yet), it would seem like a conflict with one of the plugins or the theme you are using.

To determine that, please follow this troubleshooting guide:
https://rankmath.com/kb/check-plugin-conflicts/

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

If the issue persists, please record a video screencast using a tool like Loom showing the troubleshooting and edit the first post on this ticket and include your WordPress & FTP logins in the designated Sensitive Data section.

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/

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

We really look forward to helping you.

Hello,

Sorry for the delay.

We have released the new update, could you check if it solves this issue?

You can check here for more information:
https://rankmath.com/changelog/

Hope that helps. Thank you and looking forward to your update.

Hello,

We are sorry for the delay.

The logins are not working:

Please update them.

The error is from 6th Dec. Are you still seeing that?