Error Passing null to parameter

Hello,

We apologize for the inconvenience you are facing with the Rank Math plugin on your site running PHP 8.1. The error message you shared indicates that the plugin is not compatible with your current PHP version.

To resolve this issue, you will need to upgrade your server’s PHP version to a supported one. Rank Math requires PHP 7.4 or greater to function correctly. You can refer to our knowledgebase article on how to upgrade your server’s PHP version: This Plugin Does Not Work with Your Version of PHP.

Here is a summary of the steps you need to take:

1. Upgrade your server’s PHP version to at least 7.4. If you have access to cPanel, follow the instructions in the article to select and apply the preferred PHP version.
2. Confirm the PHP version on your site by navigating to Tools → Site Health → Info in your WordPress dashboard.
3. If the PHP version is updated, you can proceed to install Rank Math from Plugins → Add New.

If you encounter any difficulties during the process, please reach out to your hosting provider for assistance in upgrading the PHP version.

We appreciate your understanding and cooperation in resolving this issue. Thank you for bringing this to our attention.

If you have any further questions or need additional assistance, feel free to contact our dedicated support team here. We are available 24/7, 365 days a year to help you.

Thank you!

Sources:
This Plugin Does Not Work with Your Version of PHP » Rank Math
Fatal Error Happening on Some Installations After 1.0.49 Update » Rank Math
Rank Math Plugin Requirements for WordPress Websites
Does Installing Rank Math Slow Down My Website? » Rank Math
This Plugin Does Not Work with Your Version of PHP » Rank Math

Hello,

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

Rank Math is fully compatible with PHP version 8.1 and the issues you’re facing were already resolved.

In this case, please make sure you’re using the latest version of the Rank Math plugin on your website: https://rankmath.com/changelog/free/

If you are unable to see an update, please clear Rank Math’s transients from WP Dashboard > Rank Math > Status & Tools > Database Tools > Remove Rank Math Transients: https://rankmath.com/kb/rank-math-status-and-tools/#rank-math-transients

Once done, please clear your website cache and see if that resolves the issue.

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

Thank you.

Hello,

This is not only an issue with our plugin but it’s also an issue with WordPress as you can see from the other warnings shown on the page.

It’s being caused by the fact that the page doesn’t have any data for the filter the_content and as such the functions that rely on it to make changes to its content are throwing the warning.

This won’t cause any issues on the website and you can remove this by simply disabling the error log from being visible to your users.

Don’t hesitate to get in touch if you have any other questions.