"Unexpected error" while installing themes?

When I tried to install a new theme, it did so successfully, but I also got these error messages:

Warning: 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 could not establish a secure connection to ww.wp.xz.cn. Please contact your server administrator.) in /home1/chimera/public_html/lifelines/wp-includes/update.php on line 119

Warning: 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 could not establish a secure connection to ww.wp.xz.cn. Please contact your server administrator.) in /home1/chimera/public_html/lifelines/wp-includes/update.php on line 287

Warning: 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 could not establish a secure connection to ww.wp.xz.cn. Please contact your server administrator.) in /home1/chimera/public_html/lifelines/wp-includes/update.php on line 435

It did this no matter which new theme I installed. I’m not at all technical, unfortunately, and doing all of this kind of thing is a struggle for me, so I’m not sure what to do about these errors. Can anyone help?