As I tried to start playing recently the admin page (https://slipmat.io/dj/) kept hanging the “starting the event…” notification for minutes and minutes. Then I reloaded the page in question and it said that my event was already live. Working and playing now as it should, but had some kind of a glitch while starting.
This sometimes can happen if your connection is flaky or the server happens to be very busy in that exact moment you start the event. What probably happened is that the backend (and all other ppl except you) registered the starting and it worked normally, but the admin screen missed the memo and didn’t go forward with the process
I filed a ticket #490 about improving this.