Error messages in v6.4.7

Probably since v6.4.7, Events Manager keeps spewing random error messages. I was able to solve errors happening when trying to create a recurring event by deleting the files in wp-content/plugin/events-manager, downloading the zip file of the plugin again and unpacking it. But just now when creating a normal event, WordPress sends me another error message by mail, though this time at least there where no visible errors.

WordPress version 6.4.3
Active theme: Customify (version 0.4.4)
Current plugin: Events Manager (version 6.4.7.1)
PHP version 8.2.7 Error details

An error of type E_ERROR was caused in line 29 of the file /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/classes/em-datetimezone.php. Error message: Uncaught Exception: DateTimeZone::__construct(): Unknown or bad timezone (a:0:{}) in /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/classes/em-datetimezone.php:29
Stack trace: 0 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/classes/em-datetimezone.php(29): DateTimeZone->__construct() 1 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/classes/em-datetime.php(311): EM_DateTimeZone->__construct() 2 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/classes/em-datetime.php(170): EM_DateTime->getTimezone() 3 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/classes/em-event.php(1732): EM_DateTime->setTimezone() 4 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/classes/em-event.php(1653): EM_Event->get_datetime() 5 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/templates/forms/event/when/dates.php(19): EM_Event->start() 6 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/templates/forms/event/when.php(10): include(‘…’) 7 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/events-manager.php(828): include(‘…’) 8 /var/www/wordpress/fsmuw/wp-content/plugins/events-manager/classes/em-event-post-admin.php(320): em_locate_template() 9 /var/www/wordpress/fsmuw/wp-admin/includes/template.php(1456): EM_Event_Post_Admin::meta_box_date() 10 /var/www/wordpress/fsmuw/wp-admin/edit-form-advanced.php(707): do_meta_boxes() 11 /var/www/wordpress/fsmuw/wp-admin/post.php(206): require(‘…’) 12 {main}

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