An unexpected error occurred…

I am very new to this, so please be patient if I have to ask for instructions to be clarified!

So I’m trying to install a theme for my new site. In particular, I’d like to install the Hum theme that I have used on one of my wordpress.com sites. I installed WordPress using Softacular. Every time that I attempt to search for themes, I get the following error message:

“An unexpected error occurred. Something may be wrong with www.ads-software.com or this server’s configuration. If you continue to have problems, please try the support forums.”

I appreciate your help