Whoops the page or event you are looking for is not found.

Ah yes, your hosting is using a 32-bit version of PHP. Eventbrite event IDs are normally higher than the maximum number that 32-bit understands, so it gets cut off to 2147483647 (which is an invalid event ID, hence the error). The iframe code works, since it’s just displaying code from Eventbrite.com’s own servers, which don’t have the same limitation.

Your best fix is to contact your hosting provider and have them put your account on a 64-bit PHP account.