Home Button Missing in Main Menu

While working on my new site, I've encountered a problem I haven't encountered before. The Home button doesn’t show up in the menu. I've gone to the menus option in Appearance, and it is there. I added my first post underneath it, but it didn’t seem to help. In Firefox, the page opens to a 404 error. In Chrome it shows up properly to my post–-but still no Home button. Of course, you can get to the posts page by clicking links in the sidebar, or clicking Back.

I don’t know if this is a WordPress issue or a theme issue. All of my sites are created with this theme with no issues.

I have posted at the WP forum as well. If someone could advise me, I’d be so grateful!