Hi. Are you possibly not using the latest versions of all our plugins?
Could you please make sure all your Modern Tribe plugins (and WordPress core) are at their latest versions?
Once you verify you’re on the latest versions, please test to see if the issue is still happening for you.
If you’re just seeing the error, this should get cleared up for you.
If you’re trying to code something custom and really do need the class name, please reference /wp-content/plugins/event-tickets-plus/src/Tribe/Commerce/WooCommerce/Main.php
Thanks!