Title: Fatal error: Uncaught TypeError in sidebar-navigation-handler.php
Last modified: February 16, 2026

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# Fatal error: Uncaught TypeError in sidebar-navigation-handler.php

 *  Resolved [retrovertigo](https://wordpress.org/support/users/retrovertigo/)
 * (@retrovertigo)
 * [3 months, 1 week ago](https://wordpress.org/support/topic/fatal-error-uncaught-typeerror-in-sidebar-navigation-handler-php/)
 * Hi there,
 * Encountering the following Fatal Error at the moment:
 *     ```wp-block-code
       PHP Fatal error: Uncaught TypeError: Elementor\\Modules\\EditorOne\\Components\\Sidebar_Navigation_Handler::add_body_class(): Argument #1 ($classes) must be of type string, null given, called in /var/www/html/wp-includes/class-wp-hook.php on line 341 and defined in /var/www/html/wp-content/plugins/elementor/modules/editor-one/components/sidebar-navigation-handler.php:36\nStack trace:\n#0 /var/www/html/wp-includes/class-wp-hook.php(341): Elementor\\Modules\\EditorOne\\Components\\Sidebar_Navigation_Handler->add_body_class(NULL)\n#1 /var/www/html/wp-includes/plugin.php(205): WP_Hook->apply_filters(NULL, Array)\n#2 /var/www/html/wp-admin/admin-header.php(252): apply_filters('admin_body_clas...', '')\n#3 /var/www/html/wp-admin/index.php(137): require_once('/var/www/html/w...')\n#4 {main}\n thrown in /var/www/html/wp-content/plugins/elementor/modules/editor-one/components/sidebar-navigation-handler.php on line 36
       ```
   
 * Elementor Version 3.35.4
   WordPress Version 6.9.1PHP 8.4
 * Thanks

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Plugin Support [Milos](https://wordpress.org/support/users/miloss84/)
 * (@miloss84)
 * [3 months, 1 week ago](https://wordpress.org/support/topic/fatal-error-uncaught-typeerror-in-sidebar-navigation-handler-php/#post-18823627)
 * Hi there,
 * Thanks for contacting us and hope you are doing well and having a great day.
 * To rule out the possibility of a plugin or theme conflict, please deactivate 
   all your plugins (besides Elementor ). If it solves the issue reactivate them
   one by one to find the culprit. If it didn’t help, switch your theme (temporarily)
   to a default WP theme such as Twenty Nineteen and see if it makes any difference.
 * I am looking forward to hearing back from you soon.
 * Kind regards,
 *  Plugin Support [Soyket](https://wordpress.org/support/users/soyele/)
 * (@soyele)
 * [1 month, 1 week ago](https://wordpress.org/support/topic/fatal-error-uncaught-typeerror-in-sidebar-navigation-handler-php/#post-18884644)
 * Hi, 
   Due to inactivity I will go ahead and close this issue. Don’t hesitate to
   create a new support ticket for a new issue. Regards,

Viewing 2 replies - 1 through 2 (of 2 total)

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 * 2 replies
 * 3 participants
 * Last reply from: [Soyket](https://wordpress.org/support/users/soyele/)
 * Last activity: [1 month, 1 week ago](https://wordpress.org/support/topic/fatal-error-uncaught-typeerror-in-sidebar-navigation-handler-php/#post-18884644)
 * Status: resolved