The Keychain Access Insert your password and click “Modify Keychain”. You will be asked to put in your password to approve the Keychain modification,.The following message will popup, change the Keychain to “System” and click ‘Add’. Locate the certificate file (.CER) you have received from your system administrator and double click it.Open the Keychain Access application, you can find it in the Launchpad or find it with Spotlight.The following guide was written by a colleague of mine, Lior Gilboa and it explain how to install a root CA certificate on a MAC client: Those root CA certificates are required in order to sign-in into Lync rather it’s on the internal or external network. Recently we got some support request tickets regarding MAC clients which weren’t able to sign-in into Lync because they were missing the necessary root CA certificates.
