Hi ermenegildo.iussa,
We have moved our theme options settings to customizer due to change of WordPress guidelines. We have only changed the global settings value. If you are using this below code in your child theme:
Replace below code
global $interface_theme_default;
$options = $interface_theme_default;
and use
global $options, $array_of_default_settings;
$options = wp_parse_args( get_option( 'interface_theme_options', array() ), interface_get_option_defaults());
If you are having this issue in your child theme then you can download from here the old version.
Thank You!