Warning: Undefined array key "value" in abstract-acf-location.php

This thread is resolved. Here is a description of the problem and solution.

Problem:
The client is experiencing 'Undefined array key "value"' errors when translating a CF7 form and other elements using WPML with Advanced Custom Fields Pro. The errors occur specifically in the Spanish translations and are related to the settings of ACF field groups.
Solution:
1. Ensure that the ACF Pro plugin is updated to version 6.4.3 or higher.
2. Set the ACF Field Groups to 'Not translatable' in WPML > Settings > Custom Post Type Translation.
3. Remove any duplicated field groups for languages other than the default site language.
4. After making these adjustments, re-translate the affected content.
5. If the issue persists, check if all field groups have a location setting and that they are not set for a post type that no longer exists on the site.

It's important to note that setting field groups to 'Translatable' is not recommended using the ACF Multilingual addon. For more details on configuring ACF with WPML, visit WPML's ACF documentation.

If this solution does not resolve your issue, or if it seems outdated or irrelevant to your case, please open a new support ticket. We also highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins.

This is the technical support forum for WPML - the multilingual WordPress plugin.

Everyone can read, but only WPML clients can post here. WPML team is replying on the forum 6 days per week, 22 hours per day.

Tagged: Documentation request

This topic contains 14 replies, has 1 voice.

Last updated by Andreas W. 2 months, 2 weeks ago.

Assisted by: Andreas W..

Author	Posts
August 6, 2025 at 9:27 pm #17300858
mikeS-64	Background of the issue: I am trying to translate a CF7 form into Spanish and I encounter error messages on the right sidebar. The issue can be seen on this page: hidden link Symptoms: Warning: Undefined array key "value" in /www/wwwkeytalkcom_402/public/wp-content/plugins/advanced-custom-fields-pro/includes/locations/abstract-acf-location.php on lines 174 and 177. Questions: How can I resolve the 'Undefined array key "value"' error when translating a CF7 form? Is there a compatibility issue between WPML and Advanced Custom Fields Pro?
August 7, 2025 at 5:02 pm #17303551
mikeS-64	I wanted to translate the footer as well in ES but I now get the following error thrown as well: Warning: Undefined array key "value" in /www/wwwkeytalkcom_402/public/wp-content/plugins/advanced-custom-fields-pro/includes/locations/abstract-acf-location.php on line 174 For the language "IT" the footer disappeared.
August 7, 2025 at 5:07 pm #17303553
mikeS-64	The translation of the footer still needs to be reviewed but it does not appear in the translation queue. In the "translation management / translation dashboard / elementor templates" the Elementor Footer template is gone?
August 8, 2025 at 6:44 am #17304402
mikeS-64	Someone the separate language pages for the footer appeared and I was able to translate them. But the error message : Warning: Undefined array key "value" in /www/wwwkeytalkcom_402/public/wp-content/plugins/advanced-custom-fields-pro/includes/locations/abstract-acf-location.php on lines 174 and 177. still persist for the Spanish language.
August 8, 2025 at 7:01 am #17304440
mikeS-64	For ES the titles of the pages are not shown in WP Admin / pages. There getting the same error message "Warning: Undefined array key "value" in /www/wwwkeytalkcom_402/public/wp-content/plugins/advanced-custom-fields-pro/includes/locations/abstract-acf-location.php on lines 174"
August 9, 2025 at 9:17 am #17306643
mikeS-64	Added screenshots so you can see where the error messages appear.
August 9, 2025 at 1:35 pm #17306873
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	Hello, The error appears to occur on ACF Pro, and it looks like they released a security update that might be tackling this. Could you please install ACF Pro 6.4.3 make sure to update the affected original contents, and then translate them again. Please reach out again in case the issue persists afterwards. Best regards Andreas
August 9, 2025 at 3:35 pm #17306978
mikeS-64	Hi Andreas, I already installed v 6.4.3 but the issue persists. Warning: Undefined array key "value" in /www/wwwkeytalkcom_402/public/wp-content/plugins/advanced-custom-fields-pro/includes/locations/abstract-acf-location.php on line 174 Warning: Undefined array key "value" in /www/wwwkeytalkcom_402/public/wp-content/plugins/advanced-custom-fields-pro/includes/locations/abstract-acf-location.php on line 177 Warning: Cannot modify header information - headers already sent by (output started at /www/wwwkeytalkcom_402/public/wp-content/plugins/advanced-custom-fields-pro/includes/locations/abstract-acf-location.php:177) in /www/wwwkeytalkcom_402/public/wp/wp-admin/admin-header.php on line 14
August 9, 2025 at 4:23 pm #17307006
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	Did you already revise all your field groups and make sure that they all have a location setting? Also, please verify if they might still have a location setting set for a post type that no longer exists on the site. If this will not clarify the cause of the issue, we can take further steps.
August 9, 2025 at 6:14 pm #17307047
mikeS-64	Could you please give me some more information on how I can check the things that you have mentioned? I'm not well versed with ACF / WPML as someone else set this up. I do saw in ACF / Field Groups and for ES that the same error messages are shown in the "Title" column.
August 9, 2025 at 7:26 pm #17307064
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	Taking a closer look at the provided debug information, it looks like you have set the ACF Field Groups inside WPML > Settings > Custom Post Type Translation to "Translatable", which is not recommended. Please set the ACF Field Groups to "Not translatable" and remove any duplicated field groups from the site. If this does not solve the issue, please let me know.
August 9, 2025 at 7:40 pm #17307072
mikeS-64	I have set ACF Field groups to "Not translatable". But when I go to ACF Field Groups i see for each language 13 entries. English only has 5. But It is only ES that gives this PHP error. The other languages, besides EN, shows title in the correct way. Where would I find these "duplicate" field groups that you are referring to? In the ACF or WPML section in the admin dashboard?
August 9, 2025 at 9:42 pm #17307128
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	It is likely that you get the error in ES because there exists a field group in this second language, which is not recommended. Once you set the ACF Field Groups to "Not translatable", all translated field groups will be assigned to the site's default language. Please go to WPML > Settings > Custom Post Type Translation and set the "ACF Field Groups" again to "Translatable". Now, go to ACF and on the list view of your field groups, use the language filter and delete all translated field groups. After that, set the ACF Field Groups again to "Not translatable". Now, please translate and update the translation for affected forms or pages again, and let me know if the error persists.
August 9, 2025 at 9:58 pm #17307132
mikeS-64	It seems to work! I removed all these additional pages in all languages besides EN and the error messages with the ES language disappeared. Why did it happen with the ES language only?
August 12, 2025 at 2:48 pm #17314009
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	The problem must have been that the field groups were translated. We no longer recommend setting field groups to "Translatable" when using ACF without out ACF Multilingual addon. There is no need to translate the groups. --- For further information, you can find WPML's ACF documentation here: https://wpml.org/documentation/related-projects/translate-sites-built-with-acf/