If you’re seeing a “SEC_ERROR_EXPIRED_CERTIFICATE” error while browsing any website, you’re not alone! This is a common error that’s associated with a website’s Secure Socket Layer (SSL) certificate. Website owners install an SSL certificate to secure the data that transfers between a website visitor’s browser and website’s server. SSL certificates are issued for a maximum of two years, and they must be renewed before or at the time of its expiry date. If the SSL certificate is not renewed, all web browsers will display the SEC_ERROR_EXPIRED_CERTIFICATE error for that site.