Often, if you can't publish a new event, it's because you have reached the maximum number of active event websites for your current plan.
We recommend taking a look at the Past Events tab on your My Events page. If any of your previous events still have a Live status, you will need to unpublish by following these steps: support.eventcreate.com/en/articles/2589803-how-to-delete-or-unpublish-an-event.
Or, to upgrade your account to publish additional events, go to: eventcreate.com/plan.