Hi Tiina,
Thanks so much for reaching out!
With the latest update of Event Tickets Plus, we completely redid the way that the ticket editor looks and functions. Because of this, it may no longer work with an expired license.
As stated here, “you will not be able to download new updates, which means you won’t get new features or bug fixes.” Essentially, with an expired license, your plugin can only work for so long without updating, because updates contain features and fixes that keep your plugin working.
I apologize for any inconvenience that this has caused you and your client. Please let me know if you have any other questions.
Thanks,
Jaime