Events are marked invalid and not displayed in calendar

After upgrading to Version 3.7.11 the newly created events are marked ‘ invalid event ‘ (in deutsch “ Ungültige Veranstaltung “) in the events overview. And they are not displayed in the calendar overview. I did a left right comparison with former created events. The only difference i could notice is that in the new events a repetition pattern is set. I did not find any debug settings for analyzing the problem myself. ================ Installation Data ==================== ==My Calendar:== Version: 3.7.11 DB Version: 3.7.8 URI: anonymized CSS: Requester Email: anonymized Admin Email: anonymized ==WordPress:== Version: 6.9.4 URL: anonymized Install: anonymized Language: de Charset: UTF-8 ==Extra info:== PHP Version: 8.2.30 DB Version: 8.0.46 DB UTC Offset: +02:00 WP UTC Offset: +02:00 DB Type: InnoDB Server Software: Apache User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:151.0) Gecko/20100101 Firefox/151.0 ==Theme:== Name: Twenty Twenty-Five URI: https://wordpress.org/themes/twentytwentyfive/ Parent: keine Version: 1.4 ==Active Plugins:== Akismet Anti-spam: Spam Protection: 5.7; https://akismet.com/ isMobile() Shortcode for WordPress: 1.1.2; https://www.dixitalmedia.com/#que-hacemos My Calendar - Accessible Event Manager: 3.7.11; https://www.joedolson.com/my-calendar/ The Events Calendar: 6.16.2; UpdraftPlus - Backup/Restore: 1.26.4; https://updraftplus.com WP Statistics: 14.16.8; https://wp-statistics.com/ Same. The most recent update broke something. My apologies; it was a stupid error, and I missed it. It’s literally a missing space. Getting it fixed shortly. Thanks for your amazing responsiveness. A client texted me with the same problem this morning.