Am running Lync 14.0.6 on iMac running OS 10.8. Was previously running 10.6 and Lync ran fine. Upgraded to 10.8 and now Lync is unstable. I can log in just fine but after about a minute or two Lync drops the connection to the server and says:
"The system is unavailable now so you have been signed out of Microsoft Lync".
I can successfully login again but it just repeats the drop out.
It creates a certificate in my key chain that has an expired date and a message that it "is not yet valid". The certificate disappears when Lync drops its connection.
Any ideas?