Fatal error: Call to undefined function is_woocommerce_active()

This document helps you resolve the “Fatal error: Call to undefined function is_woocommerce_active()” error in WooCommerce. This error typically occurs because of outdated extensions or a conflict with a third-party theme.

The error message appears as:

Fatal error: Call to undefined function is_woocommerce_active()

Possible causes

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This error can be triggered by the following conditions:

• One or more WooCommerce extensions are outdated and reference a function that is not available in their current environment.
• A third-party theme calls the is_woocommerce_active() function incorrectly, causing a conflict.

Regain admin access

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A fatal error can prevent you from logging in to your WordPress admin dashboard. If you cannot access the dashboard, use one of the following methods to disable the extension or theme causing the error before proceeding with the fixes below.

• FTP or file manager: Connect to your site via File Transfer Protocol (FTP) or your hosting provider’s file manager. Navigate to wp-content/plugins/ and rename the folder of the extension triggering the error (for example, rename my-extension to my-extension-disabled). If a theme is the cause, navigate to wp-content/themes/ and rename the active theme’s folder. WordPress will fall back to a default theme.
• WP-CLI: If you have command-line access to your server, you can deactivate the offending extension by running wp plugin deactivate plugin-folder-name, or switch themes by running wp theme activate twentytwentyfive.

Once you have regained access to the dashboard, follow the steps in the sections below to resolve the underlying issue.

Update outdated extensions

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An outdated extension is the most common cause of this error. Start by checking whether all of your extensions are up to date.

1. Go to the Subscriptions page in your WooCommerce.com account dashboard and verify that all of your extensions are running the latest version, particularly any extensions that integrate with your storefront display.
2. If you have activated your subscription keys, you receive automatic update notifications in your WordPress dashboard. Apply any available updates from Dashboard > Updates.
3. If you have not activated your keys, go to Dashboard > Updates in your WordPress admin to check whether an extension update is available.

If automatic updates are not available, you can update an extension manually:

1. Download the latest version of the extension from the Downloads page in your WooCommerce.com account dashboard.
2. Unzip the downloaded file and upload its contents to your site via File Transfer Protocol (FTP).
3. Overwrite the existing files. There is no need to deactivate the extension or delete any files.

Switch from a third-party theme

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Some third-party themes call the is_woocommerce_active() function in a way that triggers this error. If all of your extensions are up to date and the error persists, test whether your theme is the cause.

1. Go to Appearance > Themes in your WordPress admin.
2. Activate a default theme such as Twenty Twenty-Five.
3. Attempt to activate the extension that was triggering the error.
4. If the extension activates successfully, the issue is with your theme. Contact the theme developer for an updated version. Do not reactivate the third-party theme until the developer provides a fix, as doing so will re-trigger the fatal error.

Questions and support

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Do you still have questions and need assistance? 

• If you’re looking to extend the core functionality shown here, we recommend reviewing available extensions in the WooCommerce Marketplace.
• Need ongoing advanced support or a customization built for WooCommerce? Hire a Woo Agency Partner.
• Are you a developer building your own WooCommerce integration or extension? Check our Developer Resources.

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