XF 1.5 Error on Email Confirmation link

When new members try to register onto my site, they get the confirmation email and the link gives them this error.

The requested page could not be found.
Any help on fixing this so new members can use their email confirmation to join the site?
@Brogan Alright! I feel like a complete idiot! The Board URL had the /index.php set up in it when the little text under said to remove that! MY BAD! Sorry for wasting your time!