Hi,
Thanks for using our Plugins. I can help out here.
Event Tickets Plus is a combination of our 4 previous ticket plugins into one. It replaces WooCommerce tickets and both should not be active.
It will be the source of all the new ticket features going forward.
We plan to support just WooCommerce Tickets to keep it working as is.
We have this guide when you are ready:
https://theeventscalendar.com/knowledgebase/moving-to-event-tickets-plus/
It will keep all your current tickets and seeings and work almost the exact same way.
Let me know if you have any follow up questions.
Thanks