I can't sign in to Lync since I upgraded to Mac OS Sierra. I have tried flushing the DNS cache, using manual connection configuration sipdir.online.lync.com:443, entering an incorrect email address then the correct one, and all the other 'fixes' I could find to no avail. I get the error 'Sign in to Microsoft Lync failed because the service is not available or you may not be connected to the internet.'
Anyone else had this issue? any suggestions for a fix?