Error Message on new theme

I’m trying to view a new theme when I go to the themes page and hit “add new”, nothing appears except for this message: “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, on the top of the page, it says: “Please Install and Active Redux Framework Plugin for Theme Option. Click Here” But then it downloads a .zip file to my computer.

Please help.