Facebook event recovery

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.

The event is probably not public, judging from its behavior.

Events have two different privacy options depending on how the admin set up the event:

1. Public Events: Anyone can add themselves to the guest list without receiving an invitation or being approved by an admin. They can see the event information and all associated content (e.g., photos, Wall posts and videos).
2. Private Events: The event cannot be found in searches. These events are by invitation only. People who have not been invited cannot view the event description, Wall, or photos. They also will not see any Feed stories about the event.

— Facebook's Help Center (emphasis mine)

I think the only thing you can do is ask the creator to invite you again.

Not a very helpful answer, but this is indeed not possible currently. It's probably for privacy reasons, same as when you're not notified of unfriendings.

Additionally (but surely less of a reason), events are often used large-scale and you'd go crazy if you get an email for each of the 300 people attending.

However, there is a slight chance that http://betterfacebook.net/ is of assistance in your case, but I never tried it myself.