Troubleshooting Common Creative Mail Plugin Errors: From PHP Conflicts to WooCommerce Crashes

Users of the Creative Mail – Easier WordPress & WooCommerce Email Marketing plugin occasionally encounter errors that can range from simple notices to full site crashes. Based on community reports and troubleshooting threads, this guide covers the most common issues and their solutions.

1. PHP Version Compatibility Error

Problem: After an update, your site crashes with a fatal error: Composer detected issues in your platform: Your Composer dependencies require a PHP version ">= 8.0.0". You are running 7.4.33.

Why it happens: A specific plugin version (e.g., 1.6.8) contained a bug where its internal dependencies were incorrectly configured for PHP 8.0+, breaking sites on older PHP versions, even though the official requirement was listed as PHP 7.2+.

Solution: The immediate fix is to update the Creative Mail plugin to version 1.6.9 or higher, which resolved this dependency issue. If your site is already crashed and you cannot access the admin dashboard, you will need to update the plugin manually via FTP/SFTP or your hosting control panel's file manager by replacing the creative-mail-by-constant-contact plugin folder with the latest version.

2. Fatal Error When Completing WooCommerce Orders

Problem: When changing order statuses to "Completed," the site crashes with an error: Uncaught Error: Attempt to modify property "billing" on null in .../CheckoutManager.php on line 781 or 810.

Why it happens: This is a bug in the plugin's code where it tries to access or modify order data that is not available (null) at the moment the woocommerce_order_status_completed action is triggered.

Solution: This type of error typically requires a code patch from the plugin developers. Check your plugin version and update to the latest available release, as the Creative Mail team has historically released fixes for such critical errors (e.g., a similar issue in version 1.5.1 was fixed in a subsequent update). If an update does not resolve the issue, you may need to temporarily deactivate the plugin while awaiting a permanent fix.

3. "List No Longer Exists" Automation Error

Problem: Contacts in a WooCommerce purchase automation are moved to a "pending" status and then removed with a status message stating they were "added to list List no longer exist.&quot>

Why it happens: This suggests a synchronization issue where an automation workflow is trying to add a contact to a specific list that has been deleted either in Creative Mail or a connected Constant Contact account.

Solution: Review your automation settings within the Creative Mail dashboard. Ensure the list specified in the automation's action still exists. You may need to recreate the automation and re-select a valid, existing list. This often requires direct debugging of the account connection.

4. Code Syntax Errors Breaking Sites

Problem: A site breaks immediately after a plugin update with errors pointing to a specific file and line number, such as a missing parameter: 'cart_tax' => wc_format_decimal( $order->get_cart_tax(), ) in EmailManager.php.

Why it happens: These are straightforward code bugs that slip into a public release, often due to a missing variable or a syntax error.

Solution: The solution is to update the plugin. The Creative Mail team has been quick to release patches for such errors (e.g., version 1.5.1 had a missing $dp parameter that was fixed in a follow-up release). Do not edit the plugin's core files yourself, as this will be overwritten by the next update and is not a sustainable fix.

5. Conflicts with Other Plugins (Caching/Optimization)

Problem: Activating Creative Mail causes warnings like "Cannot modify header information - headers already sent&quot> originating from a caching plugin (e.g., onecom-vcache).

Why it happens: This is usually caused by the Creative Mail plugin outputting warnings or notices (e.g., Constant CE4WP_EL_EVENTTYPE already defined) before the HTTP headers are sent. Caching and optimization plugins often attempt to modify headers, and if content has already been output, PHP cannot do this, resulting in a warning.

Solution: The first step is to enable debugging in WordPress to identify the exact warning causing the header output. Temporarily disable the caching plugin to confirm the conflict. The ultimate fix requires the Creative Mail developers to resolve the underlying warning, so ensure you are running the latest version of the plugin. As a temporary workaround, if the warning is not critical, your host may allow you to suppress warning messages.

General Troubleshooting Steps

• Update Everything: Always ensure WordPress, your theme, WooCommerce, and all plugins (especially Creative Mail) are updated to their latest versions. Many reported errors are patched in subsequent releases.
• Conflict Test: Deactivate all other plugins and switch to a default WordPress theme (like Twenty Twenty-One). If the error disappears, reactivate your plugins one by one to identify the conflict.
• Check PHP Version: Verify your server is running a PHP version that meets the plugin's requirements. As of recent versions, this is PHP 8.0 or higher.

Remember, this is a community-generated guide based on user reports. For persistent issues, you may need to seek specific advice tailored to your site's configuration.