Welcome to our support forums and thanks for reaching out to us. Sorry to hear about this issue, I’ll help you out with it…
If you are getting a 404 on the front-end of the site, then please go to WP-Admin > Settings > Permalinks > Save Changes, and give the authorization process a new try. If this doesn’t help please send over a screenshot of the page you are getting redirected to, from the EventBrite authorization screen.
Thanks and sorry once again for the issue,
Best,
Nico
Please let me know about it and sorry for the hassle while setting up the plugin, we are hearing many users are having troubles with the authorization and we are looking into it but we still are not sure about the cause of the issue,