We just had a similar report in this thread:
Is this on a new server or did something change recently with your hosting setup?
Got another error message on a different site:
Deprecated: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in /services/webpages/m/w/mwisilo.com/public/cmsAdmin/lib/login_functions.php on line 308 setPrefixedCookie: Can't set cookie, headers already sent! Output started in /services/webpages/m/w/mwisilo.com/public/cmsAdmin/lib/login_functions.php line 308.
This is what happens when you go to http://www.mwisilo.com/cmsAdmin/admin.php to login to CMSB.
Any suggestions, please?