Hey Nils,
I’m sorry to hear about this! We would love to help out, but one thing to note is that these forums are our “pre-sales questions” forums. For technical support for our free plugin, The Events Calendar, please post your question in our free support forums for that plugin at http://wordpress.org/plugins/the-events-calendar
If you have a premium license from this site, log into your account here on http://theeventscalendar.com and post your question in a premium forum—we’ll help troubleshoot from there!
Thank you,
George