Troubleshooting Common PHP Errors in Yoast SEO: 'Trying to get property of non-object'

If your WordPress error logs are filling up with PHP warnings from the Yoast SEO plugin, you're not alone. A common category of errors involves messages like Trying to get property 'permalink' of non-object or Attempt to read property "ID" on int. These errors often point to a similar underlying cause: the plugin expecting an object where it finds a different data type, like a boolean (false) or an integer.

This guide will help you understand why these errors occur and the most effective steps to resolve them.

Why Do These PHP Errors Happen?

These notices are typically not fatal errors that break your site, but they can clutter your server logs and indicate an underlying issue. Based on community reports and analysis, the root cause often involves the plugin's indexable system.

Yoast SEO creates and manages a series of database tables (indexables) that store optimized metadata for your posts, terms, and other content to improve performance. These errors frequently occur when:

• The indexables need to be rebuilt: After a migration, import, or significant change to your permalink structure, the stored data might be incomplete or corrupted.
• There's a conflict with the server environment: Variables in your wp-config.php file or server configuration (like on an Azure App Service) can define the site's URL differently than what is set in WordPress Settings > General. This mismatch can cause the plugin to generate incorrect URLs.
• A specific code path receives unexpected data: For example, a function might try to read the ->permalink or ->canonical property of a variable that is false instead of a valid object.

How to Troubleshoot and Fix These Errors

Follow these steps to diagnose and resolve the issue.

Step 1: Update Everything

First, ensure your WordPress site is running the latest versions. This includes:

• WordPress Core
• Yoast SEO Plugin
• Your Theme and All Other Plugins

The Yoast SEO team regularly releases updates that include patches for known bugs. For instance, an error present in version 24.3 may already be resolved in version 24.5. Updating is the simplest and most effective first step.

Step 2: Reset and Rebuild Yoast SEO's Indexables

If updating doesn't resolve the warnings, the next step is to reset the plugin's indexable data and allow it to rebuild correctly. This is often the definitive solution for errors related to missing properties.

1. Navigate to Yoast SEO > Tools in your WordPress admin dashboard.
2. Under the "Optimize Data" section, click the button to Start SEO Data Optimization.
3. Allow the process to complete. This can take some time on larger sites.

This process will repopulate the plugin's internal tables with fresh, accurate data, which should eliminate errors caused by corrupted or missing indexables.

Step 3: Check Your Site and Home URL Settings

Since the plugin uses your site's defined URL to generate links for sitemaps, meta tags, and breadcrumbs, a misconfiguration here can cause widespread issues.

1. Go to Settings > General in WordPress.
2. Verify that both the WordPress Address (URL) and Site Address (URL) are correct and point to your live domain.
3. If you are using a wp-config.php file that defines these constants (WP_HOME, WP_SITEURL), ensure they are also pointing to the correct, live domain and not a staging or local development URL.

Step 4: Investigate Plugin or Theme Conflicts (Advanced)

If the errors persist, a conflict with another plugin or your theme might be the culprit.

1. Temporarily switch to a default WordPress theme like Twenty Twenty-Four.
2. Deactivate all plugins except Yoast SEO.
3. Check if the error disappears.
4. If it does, reactivate your plugins one by one, checking after each activation, until you find which one causes the error to return.

This process can help you identify the conflicting software so you can seek an alternative or report the issue to its developers.

Conclusion

PHP warnings from Yoast SEO about "non-object" properties are usually a sign that the plugin's internal data needs to be refreshed or that there is a URL misconfiguration. The most reliable solution is to first update all components and then use the built-in SEO Data Optimization tool. Checking your site's fundamental URL settings is also a critical step in ensuring all generated links are correct.

For ongoing issues, the WordPress community and independent resources like BugWP.com can be valuable sources of information where users share their experiences and solutions.