Re: Lync:Mac 2011 cannot sign in

Hi Nat,

I want to collect the following information for troubleshooting:
1. When you signed in to Lync in Advanced page, did you leave the Kerberosauthentication option cleared? If not, please leave it cleared.
2. Have you tried to troubleshoot the issue by logining with an incorrect username? If not, please see:
Users may be unable to sign in unless they first use an incorrect sign-in address
1. Try to sign in to Lync Online by using an incorrect sign-in address. That is, a sign-in address that you know will not work. For example, \EmailAddress @contoso.com
Note When you do this, sign-in will fail. This is expected behavior.
2. After the sign-in fails, sign in by using the correct sign-in address. For example,EmailAddress@contoso.com.
In addition, for more detailed information to troubleshoot Lync for Mac issues in Lync Online for Office 365: http://support.microsoft.com/kb/2629861

Thanks,
April Zhou