Critical error when I try to modify my menu

Hello, when I want to modify my menu, in the window ‘add menu item’, I see the following message (translated with g.translator):
“A critical error has occurred on your website. Check the site administrator’s inbox for instructions.
Learn more about WordPress troubleshooting.”. One of the emails I received says the following:

Versione di WordPress 5.8.4
Tema corrente: enfold child (versione )
Plugin corrente: (versione )
Versione PHP 8.0.17

Dettagli dell’errore
====================
Un errore di E_ERROR è stato causato nella linea 529 del file /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php. Messaggio di errore: Uncaught Error: Call to undefined function gutenberg_can_edit_post_type() in /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php:529
Stack trace:
#0 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(389): Avia_Gutenberg->can_use_block_editor()
#1 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(424): Avia_Gutenberg->init_force_classic_post_types()
#2 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(499): Avia_Gutenberg->get_force_classic_post_types()
#3 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(628): Avia_Gutenberg->force_classic_editor()
#4 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/class-wp-hook.php(303): Avia_Gutenberg->handler_display_post_states()
#5 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/plugin.php(189): WP_Hook->apply_filters()
#6 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-admin/includes/template.php(2239): apply_filters()
#7 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/nav-menu.php(831): get_post_states()
#8 [internal function]: wp_setup_nav_menu_item()
#9 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/nav-menu.php(755): array_map()
#10 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/class-wp-customize-nav-menus.php(799): wp_get_nav_menu_items()
#11 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/class-wp-hook.php(303): WP_Customize_Nav_Menus->customize_register()
#12 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters()
#13 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/plugin.php(470): WP_Hook->do_action()
#14 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/class-wp-customize-manager.php(933): do_action()
#15 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/class-wp-hook.php(303): WP_Customize_Manager->wp_loaded()
#16 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters()
#17 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-includes/plugin.php(470): WP_Hook->do_action()
#18 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-settings.php(600): do_action()
#19 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-config.php(93): require_once(‘…’)
#20 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-load.php(50): require_once(‘…’)
#21 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-admin/admin.php(34): require_once(‘…’)
#22 /var/www/vhosts/darsenamultispazio.ra.it/httpdocs/wp-admin/customize.php(13): require_once(‘…’)
#23 {main}
thrown