-- Posted by Coreyt at 12:25 pm on Dec. 27, 2008 ----------Secure Connection Failed login.yahoo.com uses an invalid security certificate. The certificate will not be valid until 1/4/2006 9:09 AM. (Error code: sec_error_expired_certificate)    * This could be a problem with the server's configuration, or it could be someone trying to impersonate the server.    * If you have connected to this server successfully in the past, the error may be temporary, and you can try again later. _______________________________________________ That is the message my sister is getting on her computer in mozilla when trying to access yahoo mail and other sites.  She gets security errors with I.E as well and can't log on AIM. Any help is appreciated -- Posted by NetParicite at 12:31 pm on Dec. 27, 2008 check the security setting on your browser maybe someone changed em' -- Posted by rand0mguy at 5:09 pm on Dec. 27, 2008 If you persistently see this message, then the most probable explanation should be that your system time is wrong. check that. If it is right, then another possible problem is that your security settings are set not to allow SSL, if that is also not the problem then it may be the fact that firefox does not like self-singed security certificates, for more on this problem check this article out