After updating from 5.7.10 to 5.8.0, I get the following notices: Notice: Undefined index: key in /plugins/advanced-custom-fields-pro/includes/acf-field-functions.php on line 349 Notice: Undefined index: ID in /plugins/advanced-custom-fields-pro/includes/acf-field-functions.php on line 361 This is usually not a problem, but when trying to use with other plugins like https://www.wpgraphql.com/acf It causes an issue where my graphql endpoint breaks because of this function. ACF Pro version: 5.8.0 PHP version: 7.1.20 ACF Implementation: Flexible content component using cloned ACF field groups as layouts. This issue has already been reported in the support forums: https://support.advancedcustomfields.com/forums/topic/acf-field-functions-php349-undefined-index-key/ And the solution for it has been posted but no PR was ever created.