Symptoms
Assume that you configure the sign-in method of Microsoft Lync for Mac 2011 to automatic or manual. When you sign in to Lync for Mac 2011, you receive an error message that states the user credentials are incorrect.
If you change the sign-in method to alternative, you will finish the sign-in process. However, after you sign in, Lync for Mac 2011 will freeze for about 25 seconds, and will then sign out. Additionally, you receive the following error message:The Lync Server cannot be accessed (verbatim)
Resolution
To resolve this issue, install the following update:
2963369 Update 2963369 for Lync for Mac 2011 14.0.9 Note If this issue is not resolved after you apply the update, you must delete the EndpointConfiguration.cache file in the following path:
<Drive>:\Documents\Microsoft User Data\Microsoft Lync Data\<sip_user>\