Same thing is going on with Add theme option. “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.”
Add new plugin page also stats “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”
WordPress news section of dashboard home says “RSS Error: WP HTTP Error: Failed to connect to ww.wp.xz.cn port 80: Connection timed out”
My host told me that “Once your website is free from any infected files, you can unblock your domain’s outgoing port using cPanel “Port 80″ plugin.”