An unexpected error occurred. Something may be wrong with www.ads-software.com or this

Hello,
I am getting the above message when I try to add a new plugin or change the theme. I have read a few other threads and tried:

Turing off my firewall
Changing the theme to Twenty Fifteen
and waiting a day

but it is still happening. I am using bplaced as host and the website is not live yet.

I hope I have given enough information.

Many thanks in advance for the help.

Emily