I found the problem. When I remove the style.css from child theme I get on browser page:
Warning: filemtime(): stat failed for /home/campo/public_html/campo-content/themes/generatepress_child/style.css in /home/campo/public_html/campo-content/themes/generatepress/functions.php on line 256
functions.php line 256 is
wp_enqueue_style( ‘generate-child’, get_stylesheet_uri(), true, filemtime( get_stylesheet_directory() . ‘/style.css’ ), ‘all’ );
What should I change?