Deprecation of SHA-1 for SSL/TLS Certificates in Microsoft Edge and Internet Explorer 11

Beginning May 9, 2017, Microsoft released updates to Microsoft Edge and Internet Explorer 11 to block sites that are protected with a SHA-1 certificate from loading and to display an invalid certificate warning. This change will only impact SHA-1 certificates that chain to a root in the Microsoft Trusted Root Program where the end-entity certificate or the issuing intermediate uses SHA-1. Enterprise or self-signed SHA-1 certificates will not be impacted, although we recommend that all customers quickly migrate to SHA-2 based certificates. For more information, please see Windows Enforcement of SHA1 Certificates.

https://technet.microsoft.com/en-us/library/security/4010323