update to 4.30 throws an error

Site had a problem updating automatically to the latest version of this plugin.

Found this in my e-mail:

The following plugins failed to update. If there was a fatal error in the update, the previously installed version has been restored.
– Maintenance (from version 4.21 to 4.30) : https://wordpress.org/plugins/maintenance/

Did the update manually and it killed the website with an error for about a minute. Don’t know how it recovered, but a minute later the site was available again.

Then found this in my e-mail:

Een fout van het type E_ERROR werd veroorzaakt op regelnummer 217 van het bestand ~/public_html/wp-content/plugins/maintenance/maintenance.php.
Foutmelding: Uncaught Error: Failed opening required ‘~/public_html/wp-content/plugins/maintenance/includes/functions.php’ (include_path=’.:/usr/local/php83/lib/php’) in ~/public_html/wp-content/plugins/maintenance/maintenance.php:217
Stack trace:
#0 ~/public_html/wp-includes/class-wp-hook.php(341): MTNC->mtnc_includes()
#1 ~/public_html/wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters()
#2 ~/public_html/wp-includes/plugin.php(522): WP_Hook->do_action()
etc…