An error is displayed on the post creation screen.

Hello,

We apologize for the issue you are facing with the error on the post creation screen. This error seems to be related to the CMB2 library used by the Rank Math plugin. Here are a few steps you can take to troubleshoot this issue:

1. Update Plugins: Ensure that all your plugins, including Rank Math, are updated to their latest versions. Sometimes, compatibility issues arise from outdated plugins.

2. Deactivate Other Plugins: Temporarily deactivate other plugins to see if there is a conflict causing this error. If the error disappears, reactivate the plugins one by one to identify the conflicting plugin.

3. Switch Themes: Try switching to a default WordPress theme (like Twenty Twenty-One) to check if the issue persists. Sometimes, themes can conflict with plugins.

4. Check PHP Version: Ensure that your server is running a supported version of PHP (7.4 or greater). You can check this in your WordPress dashboard under Tools → Site Health → Info.

5. Repair Action Scheduler: If you suspect that the issue might be related to the Action Scheduler, you can use the Repair Action Scheduler plugin available here to fix it automatically.

If these steps do not resolve the issue, please reply to this ticket with your site URL so that a human agent from our support team can assist you further. Thank you for raising this concern, and we hope to help you resolve it soon!

Sources:
Fatal Error Happening on Some Installations After 1.0.49 Update » Rank Math

Hello,

Thank you for your query and we are so sorry about the trouble this must have caused.

Please make sure you’re using the latest versions of the Rank Math free (v1.0.250) and PRO (v3.0.93) plugins on your website: https://rankmath.com/changelog/

If the issue persists, 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/

Looking forward to helping you.

Thank you.

Hello,

We are glad we could address your concern.

Please feel free to create a new forum topic if you do have another question in the future.

It will be our pleasure to assist you again.

Thank you.