Page not found since update

I am having trouble trying to figure out why a page cannot be found on my website. I have the main page on the menu bar, but you cannot access it when you click on the link. Also, when I type the URL for a subpage from the menu option it still does not navigate to the page.

I am assuming it is an error in the settings, but I cannot figure out what. Any help would be appreciated, thank you in advance.