wpsnoop Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6()

If you are dealing with a WordPress issue where a PHP Function action_scheduler_register_3_dot_1_dot_6() was already declared it is most likely due to a plugin/theme conflict.

wpsnoop scanned and analyzed over 100,000 WordPress plugins and themes to find and locate potential conflicts including functions that share the same name.

This page has information on the 8 places where that function is declared and used in WordPress plugins and themes.

Note: Our database currently only taps into the free themes and plugins available in the publicly available WordPress plugins and themes, if your site uses paid plugins, themes or custom code there may be additional conflicts.


Our database has uncovered 8 different instances of potential conflicts where different plugins or themes share the function name.

Examples of this error include:

PHP Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6() (previously declared in wp-content/plugins/wc-importer-for-reviso/libraries/action-scheduler/action-scheduler.php:37)

This file is part of the WordPress plugin WC Importer for Reviso and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6() (previously declared in wp-content/plugins/wp-mail-manager/libraries/action-scheduler/action-scheduler.php:37)

This file is part of the WordPress plugin WP PHP & SMTP Mail Check and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6() (previously declared in wp-content/plugins/come-back/wp-content/plugins/action-scheduler/action-scheduler.php:37)

This file is part of the WordPress plugin Come Back! and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6() (previously declared in wp-content/plugins/all-in-one-seo-pack/vendor/woocommerce/action-scheduler/action-scheduler.php:37)

This file is part of the WordPress plugin All in One SEO and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6() (previously declared in wp-content/plugins/pmpro-discord-add-on/libraries/action-scheduler/action-scheduler.php:37)

This file is part of the WordPress plugin Connect Paid Memberships Pro to Discord and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6() (previously declared in wp-content/plugins/wpmail-pro/includes/libraries/action-scheduler/action-scheduler.php:37)

This file is part of the WordPress plugin WP Mail Pro and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6() (previously declared in wp-content/plugins/imageseo/vendor/woocommerce/action-scheduler/action-scheduler.php:37)

This file is part of the WordPress plugin Image SEO and could be interacting with another theme or plugin and causing a fatal error.

PHP Fatal error: Cannot redeclare action_scheduler_register_3_dot_1_dot_6() (previously declared in wp-content/plugins/wpscan/libraries/action-scheduler/action-scheduler.php:37)

This file is part of the WordPress plugin WPScan and could be interacting with another theme or plugin and causing a fatal error.

The error occurs because two (or more) plugins that you are using are both trying to declare a function with the same name.