Individual pages not loading after 2.5.1 –> 2.6 Upgrade

I feel this one is a bit odd to me. I have done the upgrades to my site before so I know how it works. I run the site on my server locally and have never had issues like this one.

If I visit my site, it loads the main page AND the most recent posts with their content, however if I visit ANY other site off the main page, it displays the Error 404 – Page Not Found error. The database is obviously working because I can see the posts on the main page.

https://www.vastreality.com

Any ideas?

Yes, I have moved ALL the files over, disabled plugins, and even tried the new default layout, all display with the same outcome. I made sure to to update the wp-config.php file as well.

Thanks in advance,

Jerod