Icon picker fatal error

Bắt đầu tại includes/fields/class-acf-field-icon_picker.php dòng 132 và tái hiện lỗi với tab tùy chỉnh cùng các bộ lọc biểu tượng được hiển thị trong issue. Sử dụng cấu hình block ACF được cung cấp và các phiên bản WordPress/PHP để xác nhận đường dẫn render bị lỗi. Hoàn thành khi trình chỉnh sửa trang tải block với bộ biểu tượng tùy chỉnh mà không gặp lỗi nghiêm trọng.

Describe the bug
When using the icon picker field type in a custom ACF block with a custom icon set I am getting the following error when trying to edit a page where that block is used:

Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /var/www/html/wp-content/plugins/advanced-custom-fields-pro/includes/fields/class-acf-field-icon_picker.php:132 Stack trace: #0 /var/www/html/wp-includes/class-wp-hook.php(324): acf_field_icon_picker->render_field(Array) #1 /var/www/html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array) #2 /var/www/html/wp-includes/plugin.php(565): WP_Hook->do_action(Array) #3 /var/www/html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-hook-functions.php(113): do_action_ref_array('acf/render_fiel...', Array) #4 /var/www/html/wp-includes/class-wp-hook.php(324): _acf_apply_hook_variations(Array) #5 /var/www/html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array) #6 /var/www/html/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #7 /var/www/html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-field-functions.php(807): do_action('acf/render_fiel...', Array) #8 /var/www/html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-field-functions.php(763): acf_render_field(Array) #9 /var/www/html/wp-content/plugins/advanced-custom-fields-pro/includes/acf-field-functions.php(614): acf_render_field_wrap(Array, 'div', 'field') #10 /var/www/html/wp-content/plugins/advanced-custom-fields-pro/pro/blocks.php(613): acf_render_fields(Array, 'block_32caf81ff...', 'div', 'field') #11 /var/www/html/wp-content/plugins/advanced-custom-fields-pro/pro/blocks.php(543): acf_rendered_block(Array, '', true, 1307, Object(WP_Block)) #12 /var/www/html/wp-includes/class-wp-block.php(586): acf_render_block_callback(Array, '', Object(WP_Block)) #13 /var/www/html/wp-includes/blocks.php(2358): WP_Block->render() #14 /var/www/html/wp-includes/blocks.php(2410): render_block(Array) #15 /var/www/html/wp-includes/class-wp-hook.php(324): do_blocks('<!-- wp:acf/her...') #16 /var/www/html/wp-includes/plugin.php(205): WP_Hook->apply_filters('<!-- wp:acf/her...', Array) #17 /var/www/html/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php(1961): apply_filters('the_content', '<!-- wp:acf/her...') #18 /var/www/html/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php(655): WP_REST_Posts_Controller->prepare_item_for_response(Object(WP_Post), Object(WP_REST_Request)) #19 /var/www/html/wp-includes/rest-api/class-wp-rest-server.php(1292): WP_REST_Posts_Controller->get_item(Object(WP_REST_Request)) #20 /var/www/html/wp-includes/rest-api/class-wp-rest-server.php(1125): WP_REST_Server->respond_to_request(Object(WP_REST_Request), '/wp/v2/pages/(?...', Array, NULL) #21 /var/www/html/wp-includes/rest-api.php(586): WP_REST_Server->dispatch(Object(WP_REST_Request)) #22 /var/www/html/wp-includes/rest-api.php(2973): rest_do_request(Object(WP_REST_Request)) #23 [internal function]: rest_preload_api_request(Array, '/wp/v2/pages/13...') #24 /var/www/html/wp-includes/block-editor.php(754): array_reduce(Array, 'rest_preload_ap...', Array) #25 /var/www/html/wp-admin/edit-form-blocks.php(114): block_editor_rest_api_preload(Array, Object(WP_Block_Editor_Context)) #26 /var/www/html/wp-admin/post.php(187): require('/var/www/html/w...') #27 {main} thrown in /var/www/html/wp-content/plugins/advanced-custom-fields-pro/includes/fields/class-acf-field-icon_picker.php on line 132

To Reproduce
Steps to reproduce the behavior:

1. Create an ACF block with an icon picker field with a custom icon set.
2. Use the following code (or similar) in functions.php to manage the custom icon set

add_filter('acf/fields/icon_picker/tabs', function(array $tabs): array {
    $tabs['nwlp'] = 'NWLP';
    return $tabs;
});

add_filter('acf/fields/icon_picker/nwlp/icons', function(array $icons): array {
    $base_url = get_template_directory_uri() . '/assets/images/icons/';

    return [
        [
            'url'   => $base_url . 'accreditations.svg',
            'key'   => 'accreditations',
            'label' => 'Accreditations',
        ],
        [
            'url'   => $base_url . 'audio-podcast.svg',
            'key'   => 'audio-podcast',
            'label' => 'Audio podcast',
        ]
    ];
});

3. Try to insert/edit a page where this block is embedded and the error should show.

Expected behavior
No error to show

Code

{
    "key": "group_687639d742f8f",
    "title": "Block: Icon",
    "fields": [
        {
            "key": "field_687639d70f893",
            "label": "Icon",
            "name": "icon",
            "aria-label": "",
            "type": "icon_picker",
            "instructions": "",
            "required": 0,
            "conditional_logic": 0,
            "wrapper": {
                "width": "",
                "class": "",
                "id": ""
            },
            "tabs": [
                "nwlp"
            ],
            "return_format": "array",
            "allow_in_bindings": 0,
            "library": "all",
            "default_value": {
                "type": null,
                "value": null
            }
        },
        {
            "key": "field_68763a145e4e2",
            "label": "Icon Colour",
            "name": "icon_colour",
            "aria-label": "",
            "type": "select",
            "instructions": "",
            "required": 0,
            "conditional_logic": 0,
            "wrapper": {
                "width": "",
                "class": "",
                "id": ""
            },
            "choices": {
                "blue": "Blue",
                "green": "Green",
                "pink": "Pink"
            },
            "default_value": false,
            "return_format": "value",
            "multiple": 0,
            "allow_null": 0,
            "allow_in_bindings": 0,
            "ui": 0,
            "ajax": 0,
            "placeholder": "",
            "create_options": 0,
            "save_options": 0
        }
    ],
    "location": [
        [
            {
                "param": "block",
                "operator": "==",
                "value": "acf\/icon"
            }
        ]
    ],
    "menu_order": 0,
    "position": "normal",
    "style": "default",
    "label_placement": "top",
    "instruction_placement": "label",
    "hide_on_screen": "",
    "active": true,
    "description": "",
    "show_in_rest": 0,
    "modified": 1752583984
}

Version Information:

• WordPress Version 6.8.2
• PHP Version 8.2.28
• ACF Version ACF Pro 6.4.3
• Browser Chrome 138