404 error page not found

Hello there. I have a multisite and i have an issue.
Before one hour the most of the webpages in my site when someone open them send the message tha 404 error page has not found. But the pages are in my site and only in the preview situation i can see them. Only two pages work and the others as the cart, the wishlist and some other doesn’t work. What can i do to fix it??

The page I need help with: [log in to see the link]