Uncaught TypeError: md5(): Argument #1 ($string) must be of type string, array given

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Tagged: Documentation request

This topic contains 1 replies, has 0 voices.

Last updated by Christopher Amirian 3 days, 15 hours ago.

Assisted by: Christopher Amirian.

Author	Posts
May 13, 2026 at 8:57 am #18032231
pietR-2	Hello, I would like to report a bug (or regression): When i work on a option page of ACF and switch to another language i get this error when saving: [12-May-2026 12:06:42 UTC] PHP Fatal error: Uncaught TypeError: md5(): Argument #1 ($string) must be of type string, array given in /data/web/sites/example.com/public_html/wp-content/plugins/acfml/classes/Strings/Package.php:174 Stack trace: #0 /data/web/sites/example.com/public_html/wp-content/plugins/acfml/classes/Strings/Package.php(174): md5() #1 /data/web/sites/example.com/public_html/wp-content/plugins/acfml/classes/Options/EditorHooks.php(313): ACFMLStringsPackage::getStringName() #2 /data/web/sites/example.com/public_html/wp-content/plugins/acfml/classes/Options/EditorHooks.php(296): ACFMLOptionsEditorHooks->registerFieldTranslation() #3 /data/web/sites/example.com/public_html/wp-content/plugins/acfml/classes/Options/EditorHooks.php(165): ACFMLOptionsEditorHooks->onUpdateTranslationValue() #4 /data/web/sites/example.com/public_html/wp-includes/class-wp-hook.php(343): ACFMLOptionsEditorHooks->onUpdateValue() #5 /data/web/sites/example.com/public_html/wp-includes/plugin.php(205): WP_Hook->apply_filters() #6 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-value-functions.php(244): apply_filters() #7 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/pro/fields/class-acf-field-repeater.php(557): acf_update_value() #8 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/pro/fields/class-acf-field-repeater.php(731): acf_field_repeater->update_row() #9 /data/web/sites/example.com/public_html/wp-includes/class-wp-hook.php(343): acf_field_repeater->update_value() #10 /data/web/sites/example.com/public_html/wp-includes/plugin.php(256): WP_Hook->apply_filters() #11 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-hook-functions.php(118): apply_filters_ref_array() #12 /data/web/sites/example.com/public_html/wp-includes/class-wp-hook.php(341): _acf_apply_hook_variations() #13 /data/web/sites/example.com/public_html/wp-includes/plugin.php(205): WP_Hook->apply_filters() #14 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-value-functions.php(244): apply_filters() #15 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-value-functions.php(287): acf_update_value() #16 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-form-functions.php(174): acf_update_values() #17 /data/web/sites/example.com/public_html/wp-includes/class-wp-hook.php(341): _acf_do_save_post() #18 /data/web/sites/example.com/public_html/wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters() #19 /data/web/sites/example.com/public_html/wp-includes/plugin.php(522): WP_Hook->do_action() #20 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-form-functions.php(152): do_action() #21 /data/web/sites/example.com/public_html/wp-content/plugins/advanced-custom-fields-pro/pro/admin/admin-options-page.php(100): acf_save_post() #22 /data/web/sites/example.com/public_html/wp-includes/class-wp-hook.php(341): acf_admin_options_page->admin_load() #23 /data/web/sites/example.com/public_html/wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters() #24 /data/web/sites/example.com/public_html/wp-includes/plugin.php(522): WP_Hook->do_action() #25 /data/web/sites/example.com/public_html/wp-admin/admin.php(242): do_action() #26 {main} Plugins: Advanced Custom Fields Multilingual 2.2.2
May 13, 2026 at 9:55 am #18032482
Christopher Amirian WPML Supporter since 07/2020 Languages: English (English ) Timezone: Asia/Yerevan (GMT+04:00)	Hello, Welcome to WPML support. The chat was disconnected, which is why we created this ticket. If you get a chance to relocate the issue here: hidden link That will be great as we will have something to check. As mentioned in the chat, after updating the WPML-related plugin, please do the following steps: - IMPORTANT STEP! Create a backup of your website. Or better approach will be to test this on a copy/staging version of the website to avoid any disruption of a live website. - Switch to the default theme such as "TwentyTwenty" by going to "WordPress Dashboard > Appearance > themes". - Go to "WordPress Dashboard > Plugins" and deactivate all plugins except: . WPML Multilingual CMS . WPML String translation . ACF . ACFML . WooCommerce . WooCommerce Multilingual - Check if you can still recreate the issue. - If not, re-activate your plugins one by one and check the issue each time to find out the plugin that causes the problem. We understand that providing the website staging version is hard for further investigation, but that will be our only way to do debugging there. Maybe if you could provide any sort of restricted version that it will not expose the information you do not want to share but it shows the error that would be great. Thanks.