8 common SSL / TLS errors with verified solutions.
The browser cannot establish a secure SSL/TLS connection because the server and browser cannot agree on a protocol version or cipher suite.
Server and browser cannot agree on SSL/TLS protocol version or cipher suite.
SSL certificate is not signed by a trusted Certificate Authority.
SSL certificate has expired or is not yet valid.
Domain name doesn't match any domain in the SSL certificate.
SSL/TLS handshake between client and server failed to complete.
HTTPS page loading resources over HTTP. Modern browsers block mixed content.
HSTS configuration creating a redirect loop between HTTP and HTTPS.