Add themes – Nothing loads – An unexpected error occurred!

When I go to Appearance > Themes > Add themes, nothing loads and I get this error: “An unexpected error occurred. Something may be wrong with www.remarpro.com or this server’s configuration. If you continue to have problems, please try the support forums.”

Also when I go to add a new plugin and search, it just loads and the circle just spins (Unless I hit F5 then the search results will load).

I am running a VPS with CentOS 6 + cPanel. I have another VPS with the same setup and with NO issues. What is going wrong with this install?

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