Google and Mozilla were concerned that Symantec’s digital certificate business had lost quality control. The certificates are crucial for security, scrambling web traffic so it’s unreadable to outsiders. If the certificates are not replaced, Google’s Chrome browser will warn of an invalid certificate in place and that the site should not be trusted. Google says the race will be on to replace those certificates issued before June 1, 2016, in advance of the release of Chrome 66. That version of the browser will be released in beta on March 15, 2018, and to stable users around April 17, 2018.”]
Source: https://www.cuinfosecurity.com/dont-delay-replace-symantec-tlsssl-certs-now-a-10283