Troubleshooting 'Cannot read properties of undefined' Errors in All in One SEO

Many WordPress administrators encounter JavaScript errors related to the All in One SEO plugin, often preventing access to key admin areas like the post editor or widgets screen. These errors typically manifest in the browser console with messages like Cannot read properties of undefined (reading 'getEditedPostAttribute'), Cannot read properties of undefined (reading 'includes'), or Cannot read properties of undefined (reading '_s'). This guide will help you understand why these conflicts happen and walk you through the most effective steps to resolve them.

Why These Errors Occur

These 'undefined' errors are almost always the result of a conflict. The All in One SEO plugin interacts heavily with the WordPress block editor (Gutenberg), which relies on a complex JavaScript environment. When another plugin, theme, or server-level optimization interferes with how these scripts load or execute, it can break functionality and trigger these console errors. Common causes include:

• Aggressive Caching: Server, browser, or Content Delivery Network (CDN) cache serving outdated JavaScript files.
• Asset Optimization: Plugins that combine, minify, or delay the loading of JavaScript files can break the proper order of dependencies.
• Plugin/Theme Conflicts: Another extension may be loading an incompatible version of a library (like React) or modifying the same admin screens.

How to Troubleshoot and Fix the Issue

Follow these steps in order. After each step, check your WordPress admin to see if the error has been resolved.

Step 1: Clear All Caches

This is the most common fix. Cached JavaScript files can become outdated after a plugin update.

1. Clear your browser cache. You can usually do this by pressing Ctrl+Shift+Delete (Windows) or Cmd+Shift+Delete (Mac) while in your browser.
2. Clear any caching from your WordPress caching plugin (e.g., WP Rocket, W3 Total Cache).
3. Clear your CDN cache (e.g., Cloudflare, StackPath).
4. If you have server-level caching (like Varnish or Redis), contact your hosting provider to have it cleared.

Step 2: Check for Conflicts

The goal here is to identify if another plugin or your theme is causing the problem.

1. Temporarily switch your WordPress theme to a default theme like Twenty Twenty-Four.
2. If the error disappears, the issue is with your original theme. Please contact your theme's support for further assistance.
3. If the error persists, move on to deactivating all plugins except for All in One SEO.
4. If the admin screens load correctly, reactivate your plugins one-by-one, checking for the error after each activation. This will help you identify the conflicting plugin.

Step 3: Disable JavaScript Optimization

If you use a plugin for performance that handles JavaScript (such as Autoptimize, WP Rocket, or WP Optimize), temporarily disable its JavaScript optimization features. This includes options for minification, concatenation, and deferred loading. See if disabling these options resolves the error.

Step 4: Ensure User Role Compatibility

Some errors, particularly the reading '_s' error, have been reported to affect users with the Editor or Author role but not Administrators. If this matches your experience, ensure all user roles have the appropriate permissions for managing SEO. The All in One SEO team suggests checking the role manager settings within the plugin's general settings to verify that no necessary capabilities have been restricted for these roles.

Getting Further Help

If you have followed all the steps above and the issue continues, you will need to gather specific information to get help from the wider community. When seeking help, be sure to provide:

• The exact text of any error messages from your browser console.
• The name of the theme you are using.
• A list of all active plugins.
• Your current versions of WordPress, PHP, and the All in One SEO plugin.

This information is crucial for others to accurately diagnose the conflict you are experiencing.