Hey @adriana08,
thanks for your message.
This is usual bracket syntax for arrays which is available since PHP 5.4 – this shouldn’t be the problem. I checked the code again.
Do you have the following code in wpgiftregistry/admin/class-wp-gift-registry-admin.php for lines 117-146?
register_post_type('wpgr_wishlist', [
'labels' => [
'name' => __('Wishlist', 'wpgiftregistry'),
'singular_name' => __('Wishlist', 'wpgiftregistry'),
'menu_name' => __('Wishlists', 'wpgiftregistry'),
'add_new_item' => __('Add new Wishlist', 'wpgiftregistry'),
'edit_item' => __('Edit Wishlist', 'wpgiftregistry'),
'new_item' => __('New Wishlist', 'wpgiftregistry'),
'search_items' => __('Search Wishlists', 'wpgiftregistry'),
'all_items' => __('All Wishlists', 'wpgiftregistry'),
],
'description' => '',
'public' => TRUE,
'publicly_queryable' => TRUE,
'show_ui' => TRUE,
'show_in_rest' => FALSE,
'rest_base' => '',
'has_archive' => FALSE,
'show_in_menu' => TRUE,
'exclude_from_search' => FALSE,
'capability_type' => 'post',
'map_meta_cap' => TRUE,
'hierarchical' => FALSE,
'rewrite' => [
'slug' => 'wishlist',
'with_front' => FALSE
],
'supports' => ['title', 'author'],
'menu_icon' => plugins_url( "../images/gift_registry_icon.png", __FILE__ ),
]);
If yes, everything should work correctly.
Best
Moritz