Hello Witold Jermołowicz,

Sorry for late reply to this,
I have tested in my locally, it seems like everything is working fine when i click delete event from the event page, is it possible provide us with your Joomla backend and FTP access so we can help you check on this issues?

Also, on event edit page it would be good to have an ability to delete the event.

By the way, thanks for your suggestion, I will consult with our developer regarding this suggestion and see how it goes.