Title: Fatal error when editing certain ACF fields
Last modified: June 4, 2026

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# Fatal error when editing certain ACF fields

 *  [yuriks2000](https://wordpress.org/support/users/yuriks2000/)
 * (@yuriks2000)
 * [4 days, 18 hours ago](https://wordpress.org/support/topic/fatal-error-when-editing-certain-acf-fields/)
 * Hello,
   Have found an issue when batch updating some fields and propose a solution.
   Have already patched it locally and on produciton, it works. Current plugin: 
   ACF QuickEdit Fields (version 3.3.8)Error Details
 * An error of type E_ERROR was caused in line 29 of the file /var/www/production/
   wp-content/plugins/acf-quickedit-fields/include/ACFQuickEdit/Fields/Traits/BulkOperationLists.
   php. Error message: Uncaught TypeError: array_merge(): Argument #2 must be of
   type array, string given in /var/www/production/wp-content/plugins/acf-quickedit-
   fields/include/ACFQuickEdit/Fields/Traits/BulkOperationLists.php:29
   Stack trace:
   0 /var/www/production/wp-content/plugins/acf-quickedit-fields/include/ACFQuickEdit/
   Fields/Traits/BulkOperationLists.php(29): array_merge() 1 /var/www/production/
   wp-content/plugins/acf-quickedit-fields/include/ACFQuickEdit/Admin/Bulkedit.php(
   209): ACFQuickEdit\Fields\PostObjectField->do_bulk_operation() 2 [internal function]:
   ACFQuickEdit\Admin\Bulkedit->process_data() 3 /var/www/production/wp-content/
   plugins/acf-quickedit-fields/include/ACFQuickEdit/Admin/Bulkedit.php(201): array_walk()
   4 /var/www/production/wp-content/plugins/acf-quickedit-fields/include/ACFQuickEdit/
   Admin/Bulkedit.php(187): ACFQuickEdit\Admin\Bulkedit->process_data() 5 /var/www/
   production/wp-content/plugins/acf-quickedit-fields/include/ACFQuickEdit/Admin/
   EditFeature.php(171): ACFQuickEdit\Admin\Bulkedit->get_save_data() 6 /var/www/
   production/wp-includes/class-wp-hook.php(326): ACFQuickEdit\Admin\EditFeature-
   >save_acf_post_meta() 7 /var/www/production/wp-includes/class-wp-hook.php(348):
   WP_Hook->apply_filters() 8 /var/www/production/wp-includes/plugin.php(517): WP_Hook-
   >do_action() 9 /var/www/production/wp-includes/post.php(5110): do_action() 10/
   var/www/production/wp-includes/post.php(5212): wp_insert_post() 11 /var/www/production/
   wp-admin/includes/post.php(709): wp_update_post() 12 /var/www/production/wp-admin/
   edit.php(194): bulk_edit_posts() 13 {main}
 * thrown
   Solution:/wp-content/plugins/acf-quickedit-fields/include/ACFQuickEdit/
   Fields/Traits/BulkOperationLists.php
 * Line 29
   $value = array_unique( array_merge( $old_value, **(array)** $new_value));

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 * 1 participant
 * Last reply from: [yuriks2000](https://wordpress.org/support/users/yuriks2000/)
 * Last activity: [4 days, 18 hours ago](https://wordpress.org/support/topic/fatal-error-when-editing-certain-acf-fields/)
 * Status: not resolved