I also am having the same problem. I tried to cancel an event using the backend admin section, “Event Status: ” and chose “Cancelled” but the update button does nothing. I tried updating another event…same thing. The backend doesn’t respond to the Update button click. When I click on Preview Changes a new window opens with the original event, but without the changes. When I go back to the backend side of the event, the “Update” button is greyed out and a grey, spinning circle is next to it. The backend is unresponsive until I reload the page.