Hello,
I updated a test site from Joomla 3.5.1 to 3.6.0, and then updated the Event Booking component to 2.8.1.
Now, the invoice template in Invoice Settings has disappeared.
Please help.
That's strange. That would not be any change causing the invoice template disappear. You can submit a support ticket sending us super admin account so that I can ask our dev to check it for you