If you need to cancel an event, firstly you need to stop selling tickets online and then you need to notify your customers about the cancellation, as well as your refund policy (e.g. whether they can request a cancellation and/or change to another date).
You can stop selling tickets online by following the steps below:
Click on the "Administration" tab
Select "edit" under the "plays" section.
From the events list on your right, select the play you want to edit.
Click on the "existing events" tab.
Select the event date you want to stop sales for, by clicking on the tickbox next to the venue name and then scroll down and click on the "activate / deactivate ticket presales".
On the pop-up window that will appear, click on the "No" tickbox under "allow online sales ?"
Εnter a message to appear to website visitors in the relevant field. Then, click on "save".
The text in the message textbox will appear when your website visitors hover their mouse over the "Book" button, which will be deactivated.
To activate the tickets presales again, follow the same procedure and on the pop-up window (see image above), choose "Yes", under "allow online sales ?'' and press "save".