Why: NET::ERR_CERT_SYMANTIC_LEGACY – Google Chrome
You may receive a message in Google Chrome about your connection is not private when you try browsing a website. The exact Google Chrome error will be NET::ERR_CERT_SYMANTIC_LEGACY. You receive this message because the website you are browsing is using an HTTP(S) certificate issued from a Symantec certificate authority and Google Chrome has already begun depreciating these certificate authorities.
Starting with Chrome 66, any certificate issued by Symantec prior to June 1, 2016 will be considered untrusted.
Starting with Chrome 70, all certificates issued by Symantec will be considered untrusted.
The slated date of release for Google Chrome 70 (which is when all Symantec CA’s will be untrusted) is October 16, 2018.
According to Wiki, Symantec currently has a market share of 12.9% of all Internet certificate authorities issued. Symantec is the 3rd largest provider of certificate authorities issued online according the W3Techs as of 2017.
Web admins – updated your CA’s! See our article on a step-by-step guide to moving to a free certificate authority - Let’s Encrypt.