Howdy Alexander,
It would seem that your theme is likely out of date. There should be no structured data on the widget whatsoever in 4.0.7. But your theme is apparently overriding this file: /tribe-events/pro/widgets/modules/single-event.php and adding the malformed structured data to it. Updating this file and removing the structured data CSS tags from it should remove this issue.
I would not worry too much about it though, it should have no impact on your SEO. The error itself indicates that Google can’t use the structured data in its listings, but that data shouldn’t be there anyways so that’s no problem. This is not at all like a 404 or something that has a negative impact on your page rank.
Does that all make sense? Did that answer your question? Please let me know.
Cheers!
– Brook