Trouble installing theme

My wordpress installation deleted some of my plug-ins, my main theme and content at random. When I now try to re-install the deleted theme I am presented with this message:

An unexpected error occurred. Something may be wrong with ww.wp.xz.cn or this server’s configuration. If you continue to have problems, please try the support forums.

I have anohter WordPress site with the same host utilising the same template – and that one is perfectly fine. The host I am using is Zippy Kid. I have access to the database/htdocs part of the site in question, but do not have access to anything else.

Could someone help me? Any suggestions on what to do?