Websites that have no or expired SSL are considered insecure. The error comes with “Your connection is not private” message, suggesting that proceeding to such site is not a good idea. NET::ERR_CERT_DATE_INVALID error is a warning message from Chrome browser which informs about expired website’s SSL certificate. Fix NET::ERR_CERT_DATE_INVALID Error on Google Chrome (Visitors guide).How to Fix NET::ERR_CERT_DATE_INVALID Error? (Webmasters).NET::ERR_CERT_DATE_INVALID on Chrome warns about site’s expired SSL certificate.