I don't have any clue about it. You can submit a support ticket sending us super admin account of your site so that we can check to see what's wrong and get it sorted for you
In admin configuration settings-->sef router settings
insert event id "yes" and save the configuration. But for past events details page not displaying when sef urls ON.
Past events page ? Maybe you want to display past events? If so, go to Events Booking -> Configuration, find the config option hide past events, set it to No and these events should be displayed
