Events Manager: Content not loading

[dabu]

Hi
I have installed the Events Manager Plugin.
The content of these pages unfortunately doesn't load. Here an example of an event with booking form etc.:
https://schreibschule-sent.ch/events/poesias

What's the reason behind this? Is there a way to load those contents?
If I insert the booking form with a shortcode, it works: https://schreibschule-sent.ch/test

That's not the solution for me (event details are missing!), but just to show that acutally the plugin would work (and it works on another WP site I tested with some other WP theme).

[Richard]

Dear @dabu

Unfortuantely i cannot debug a third-party plugin at the Moment - However! i do hope that others with experience with Events Manager will please help @dabu

Sincerely
Richard