Icon not shown with g_file_new_for_uri

Question

all. I'm trying to display an icon in my notification, see relevant code:

GIcon* gicon_from_path (const gchar* path)
{
    GFile *file = NULL;
    GIcon *tmp = NULL;
    
    file = g_file_new_for_path (path);
    tmp = g_file_icon_new (file);
    
    g_object_unref (file);
    return tmp;
}

GIcon* gicon_from_resource (const gchar* res)
{
    GFile *file = NULL;
    GIcon *tmp = NULL;
    
    file = g_file_new_for_uri (res);
    tmp = g_file_icon_new (file);
    
    g_object_unref (file);
    return tmp;
}

void send_notification (GApplication *application)
{
    GNotification *notification;
    GIcon *icon;

    //icon = gicon_from_path (PACKAGE_DATADIR "/gtk3-demo-icon_32.png");
    icon = gicon_from_resource ("resource:///button/icons/tray.png");
    notification = g_notification_new ("Hola");
    g_notification_set_body (notification, "Probando");
    if (icon)
    {
        g_print ("Have icon");
        g_notification_set_icon (notification, icon);
    }
    g_application_send_notification (application, "lunch-is-ready", notification);
    
    g_object_unref (icon);
    g_object_unref (notification);
}

void on_clicked (GtkWidget *self, gpointer user_data)
{
    PMYDATA pD = user_data; // my app data
    send_notification (G_APPLICATION (pD->app));
}

If I use gicon_from_path the icon is showed as expected. But with gicon_from_resource not only the icon is not showed, I get this messages:

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.627: g_variant_new_take_string: assertion 'string != NULL' failed

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.627: g_variant_new_variant: assertion 'value != NULL' failed

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.627: g_variant_get_type: assertion 'value != NULL' failed

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.628: g_variant_type_is_subtype_of: assertion 'g_variant_type_check (type)' failed

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.628: g_variant_builder_add_value: assertion '!GVSB(builder)->expected_type || g_variant_is_of_type (value, GVSB(builder)->expected_type)' failed

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.628: g_variant_builder_end: assertion 'GVSB(builder)->offset >= GVSB(builder)->min_items' failed

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.628: g_variant_get_type: assertion 'value != NULL' failed

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.628: g_variant_type_is_subtype_of: assertion 'g_variant_type_check (type)' failed

(gtk3_single:3256): GLib-CRITICAL **: 07:18:23.628: g_variant_builder_add_value: assertion '!GVSB(builder)->expected_type || g_variant_is_of_type (value, GVSB(builder)->expected_type)' failed

In both cases, I can see the message Have icon from g_print. So I guess is something in g_file_new_for_uri. Btw, this is my .gresource.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<!-- to use with gtk3 -->
<gresources>
    <gresource prefix="/main/icons/">
        <file alias="16x16/apps/gtk3_single.png">gtk3-demo-icon_16.png</file>
        <file alias="32x32/apps/gtk3_single.png">Cat-icon_32.png</file>
        <file alias="48x48/apps/gtk3_single.png">cat-food-hearts-icon_48.png</file>
    </gresource>
    <gresource prefix="/button/icons">
        <file alias="home.png">Home-icon_24.png</file>
        <file alias="tray.png">gtk3-demo-icon_32.png</file>
    </gresource>
    <gresource prefix="/menu/icons">
        <file alias="quit">Actions-application-exit-icon_20.png</file>
    </gresource>
</gresources>

My OS is Archlinux using gtk3 3.24.34. So, any help or ideas?