How to Fix ERR_SSL_VERSION_OR_CIPHER_MISMATCH

When you visit website running over HTTPS series of steps are performed between the browser and the server to ensure the certificate and SSL TLS connection is valid. Some of these include TLS, the certificate being checked against the authority, and decryption of the certificate. If you see this error, the first and easiest place to start is to perform SSL check on the certificate that is installed on site. We recommend using SSL check tool from Qualys SSL Labs. It's very reliable and we use it for all Kinsta clients when verifying certificates. Simply your domain into Hostname field and click on. In this particular instance, the customer migrating to Kinsta had certificate name mismatch. The site no longer exists, to IP address, where some other site is now hosted.. Another easy way to check the domain name issue on the certificate is to open up Chrome DevTools on the site. Under configuration, you the version of TLS running on the server with that certificate. If it's old, reach out to your host and ask them to update their TLS version. Do not forget that TLS 1.3 is also something to look forward to.. Another reason according to Google's for ERR SSL VERSION OR CIPHER MISMATCH is that RC4 suite was removed in Chrome version 48.  Read more