you are using wordpress as your cms.
and are you sure that you have already add page name 5?

check at your dashboard and page tab.

It seems that whenever a new post is added this problem occurs.


If you go on the main page you'll see when you go to page 2 it works page 3 it works page 4 it works but page 5 doesn't. And once there's more posts and let's say it creates a page 6, I'm sure it won't work?