I selected 'hide' for a Facebook event that I did not want to be reminded of, and now I can not even view the even when explicitly trying (it is not listed on the creators page and the page is listed as not found when I click on the link in the original email). How can I unhide the event?
It sounds like the event has been deleted. What's the time frame between hiding the event and trying to view it?
Facebook might also have locked you out of viewing the event, depending on its privacy settings. You could have removed it from "My events" instead of hiding it, by accident.
Edit: The event is probably not public, judging from its behavior.
— Facebook's Help Center (emphasis mine)
I think the only thing you can do is ask the creator to invite you again.