Back to Community
Home / Community / Plugin → Autoptimize

Troubleshooting Common Autoptimize PHP Errors and Compatibility Issues

24 threads Sep 16, 2025 Plugin → Autoptimize

Content

Autoptimize is a powerful tool for optimizing your WordPress site, but like any complex plugin, it can sometimes run into conflicts with other plugins, themes, or newer PHP versions. Based on community reports and common issues, here’s a guide to diagnosing and resolving some of the most frequent PHP-related errors.

1. Fatal Errors and White Screens (Error 500)

Symptoms: Your site returns a blank white screen or a 500 error immediately after activating or updating Autoptimize.

Common Causes:

  • Plugin or Theme Conflict: This is the most frequent cause. As seen in the sample threads, conflicts with plugins like Elementor Pro are common. The error Cannot use output buffering in output buffering display handlers often points to this.
  • Missing Files: In rare cases, a problematic update might accidentally omit a required file, causing a fatal error on lines referencing that file (e.g., Failed opening required 'ao-minify-html.php').

Solutions:

  1. Conflict Test: Deactivate all other plugins and switch to a default WordPress theme (like Twenty Twenty-Four). If the error disappears, reactivate your plugins and theme one by one to identify the culprit.
  2. Reinstall the Plugin: If a faulty update is suspected, manually delete the Autoptimize folder via FTP/SFTP and install a fresh copy from the WordPress repository.

2. PHP Deprecation and Compatibility Warnings

Symptoms: Your site functions, but your PHP error logs are filled with warnings about passing null to functions or accessing array offsets on boolean values. These are common when running PHP 8.0 or higher.

Common Causes: Newer PHP versions enforce stricter type checking. Code that worked with PHP 7.x may generate warnings when variables are null or of an unexpected type.

Solutions:

  1. Update Autoptimize: The Autoptimize team actively addresses these deprecation notices. Many fixes are already available in the latest stable versions. Ensure you are running the most current version of the plugin.
  2. Check Beta Versions: For issues not yet resolved in a stable release, a beta version is often available on GitHub that contains the necessary patches. The community frequently reports that beta versions resolve specific warnings like Trying to access array offset on value of type null.
  3. Adjust Error Reporting: On a production site, it's often recommended to disable the logging of warning-level errors to prevent log files from filling up, as these notices typically don't break site functionality.

3. Database and Configuration Errors

Symptoms: Errors when saving Autoptimize settings, such as Column 'option_value' cannot be null.

Common Causes: This is usually not a bug in Autoptimize itself but is caused by strict SQL mode settings in your MySQL database (e.g., STRICT_TRANS_TABLES).

Solutions:

  1. Contact your hosting provider and ask if they can adjust your database's sql_mode to remove the strict mode restriction, which can resolve this class of errors.

General Best Practices

  • Always Test Updates on a Staging Site: Before applying updates to your live site, test them in a staging environment that mirrors your production setup.
  • Check Your Logs: When troubleshooting, your server's PHP error log is your best friend. It provides the exact file and line number where an error occurs, which is crucial for diagnosis.
  • Community Resources: The WordPress.org support forums are an excellent resource for seeing if others are experiencing similar issues and finding workarounds.

Most issues are temporary and can be resolved through conflict testing or waiting for an official patch. By following a structured troubleshooting approach, you can often get your site back to optimal performance quickly.

Related Support Threads Support