Incorrectly issued certificates are a potential issue with Edge Server configuration.
As a best practice, always use the built-in Certificate Wizards because they automatically generate the correct names for a server role. Only the Access Edge and Web Conferencing Edge certificates need to be issued by a public certificate authority. The internal Edge certificate and A/V Authentication certificates are used only by internal clients.
Follow the guidelines to rule out certificate issues.
• Key Bit Length—The certificate bit length must be 1024, 2048, or 4096 to be supported by Lync Server.
• Template—The template used to issue the certificate should be based on the web server template. If the Lync Server Certificate Wizard is ...