Multisite gives a lot of error with font-manager.class.php

Hi there,
with the demo “App” selected, the multisite installation gives me the following warning on all the pages (only with multisite, nor using the normal way):

Warning: include(/home/customer/www/…/public_html/wp-content/uploads/avia_fonts/Flaticon/charmap.php): failed to open stream: No such file or directory in /home/customer/www/grifofinance.com/public_html/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/font-manager.class.php on line 477

Warning: include(): Failed opening ‘/home/customer/www/…/public_html/wp-content/uploads/avia_fonts/Flaticon/charmap.php’ for inclusion (include_path=’.:/usr/local/php73/pear’) in /home/customer/www/grifofinance.com/public_html/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/font-manager.class.php on line 477

Lastly, the header bar (logo, menu, socials) gets stuck in an unnatural position while scrolling the page.

I have read that in multisite installations it is necessary to change the settings and to add TXT and ZIP to the files that can be modified. I did, but nothing happens. I also read that some icon fonts need to be reloaded, but I didn’t understand anything: I tried to do it but with mediocre results.

As I am late for this work, I would need your hand to get out of this impasse otherwise I am almost completely stuck.

Many thanks!