Hi Mart,
The best way would be to login to your site as an administrator then follow the link. For me, it returns a 404 Not Found error which suggests it may have been deleted. If you are logged in as an administrator though you may be able to see it if it is in fact simply ‘private’.
Alternatively, you can try to edit it by crafting a URL like this one (again, sign yourself in as an administrator first):
http://interpromusa.com/wp-admin/post.php?post=11&action=edit
This will either let you see the event in the editor, or if it no longer exists you’ll see a message like: You attempted to edit an item that doesn’t exist. Perhaps it was deleted?
Where are you getting this link from, out of interest?