Unfortunately this did not make a difference.
Although you obviously didn’t change neither the em_get_event function nor its signature, it in fact works again when changing the $search_by param to ‘post_id’.
So when calling the function with $search_by param set to ‘post_id’ it works again.
I created an Issue and a PR on github 😉
I’ve edited the script to simply redirect to the home page defined in WordPress rather than display this message.
@ouija: The only problem is, that this is not update proof.
Would be much better by using a redirect to home url or simple 404 page. Pleas add this!