Back to Community
Home / Community / Plugin → Ewww image optimizer

Troubleshooting Common EWWW Image Optimizer PHP Errors and Warnings

31 threads Sep 11, 2025 Plugin → Ewww image optimizer

Content

EWWW Image Optimizer is a powerful tool for compressing images in WordPress, but like any complex plugin, it can sometimes generate PHP errors, warnings, and notices. These messages, often found in debug logs or on the site itself, can be alarming. This guide will help you understand and resolve the most common ones.

Understanding the Different Types of Messages

  • Notices: Non-critical messages about potential minor issues in the code (e.g., an undefined variable). The site will usually function normally.
  • Warnings: More serious than notices, indicating a problem that did not halt script execution. Functionality might be partially affected.
  • Fatal Errors: Critical errors that cause the script to stop running completely.

Common Errors and Their Solutions

1. "Unable to fork" or "exec() has been disabled" Warnings

What it looks like:
PHP Warning: exec(): Unable to fork [...]
Warning: exec() has been disabled for security reasons

Why it happens: The plugin relies on the PHP exec() function to communicate with its optimization tools. If this function is disabled in your server's PHP configuration (often via the disable_functions directive), the plugin cannot perform its core function.

How to fix it: Contact your web host and request that they enable the exec() function. Some hosts may be reluctant due to security policies. In this case, you may need to discuss alternative solutions with them or consider a host that supports the plugin's requirements.

2. Undefined Constant Notices (e.g., EWWW_IMAGE_OPTIMIZER_NOEXEC)

What it looks like:
Notice: Use of undefined constant EWWW_IMAGE_OPTIMIZER_NOEXEC - assumed 'EWWW_IMAGE_OPTIMIZER_NOEXEC'

Why it happens: This typically occurs when there is a conflict during the plugin's loading process, preventing some constants from being defined early enough. It is often a benign notice.

How to fix it: These notices are usually addressed by the EWWW Image Optimizer team in subsequent updates. Ensure your plugin is updated to the latest version. If the notices persist and are bothersome, they can often be safely ignored if the plugin is otherwise functioning. For a production site, it's considered best practice to disable WP_DEBUG logging to prevent these notices from being written.

3. Function-Related Errors (e.g., call to undefined function boolval())

What it looks like:
Fatal error: Call to undefined function boolval()

Why it happens: The plugin uses a PHP function that is not available in your version of PHP. The boolval() function, for example, was introduced in PHP 5.5.

How to fix it: The solution is to update your PHP version to at least the minimum required by the plugin. Alternatively, the EWWW Image Optimizer team often releases patches to provide backwards compatibility for older PHP versions. Updating the plugin usually resolves this.

4. Database Upgrade Prompt

What it looks like: A message stating "EWWW Image Optimizer needs to upgrade the image log table. [Upgrade]"

Why it happens: Occasionally, a plugin update requires a change to the structure of its database table to store new data or improve accuracy. Normally this is done automatically, but in some cases, a manual confirmation is required.

How to fix it: This is a normal and safe prompt. Simply click the "Upgrade" button to complete the process. The message will disappear once the update is finished.

5. Corrupt JPEG Data Warnings

What it looks like:
PHP Warning: getimagesize(): corrupt JPEG data: XXX extraneous bytes before marker

Why it happens: This warning is generated when the plugin tries to read an image file that is already corrupt or damaged before any optimization takes place. The plugin is identifying the problem, not causing it.

How to fix it: The warning itself can often be ignored. To resolve it, you would need to identify the corrupt image(s) from the log and replace them with valid versions from a backup.

General Troubleshooting Tips

  1. Update Everything: Always ensure you are running the latest version of WordPress, the EWWW Image Optimizer plugin, and your theme. Many errors are patched in subsequent releases.
  2. Check PHP Version: Confirm your server is running a supported version of PHP that meets the plugin's minimum requirements.
  3. Disable Debugging on Production Sites: Having WP_DEBUG enabled on a live site can leak sensitive information and fill logs with minor notices. It should only be used temporarily for troubleshooting.
  4. Review Server Configuration: As seen with the exec() function, some errors are rooted in server-level PHP settings (php.ini). Your web host controls these settings.

Most errors reported in the WordPress admin or debug logs are non-critical and can be resolved by updating the plugin or adjusting server settings. For persistent fatal errors or complex server configuration issues, consulting your web host is often the most effective next step.

Related Support Threads Support