Nothing is wrong, but I would like to throw something out there for someone searching on this topic that may be as frustrated as I was up until a few minutes ago.
If you want to add either your Organizer or Venue to the tooltips window, follow the info in one of these two posts:
Add Orgaziner to calendar detail overlay (Part II)
Add custom fields to tooltip in month view
But when you get to the part about adding the “data-tribejson” part and you’re all confused — you need to add it to the FIRST div at the bottom of the single-event.php page. Replacing `data-tribejson='<?php echo tribe_events_template_data( $post ); ?>’.
That little bit of information held me up for quite a while, only because working in my editor, without wordwrap on, I never noticed it past the edge of the window.
Yes, rookie error, but sharing the info may help someone not pull their hair out later. 😉