Troubleshooting Lync FOR MAC client issue

1.Cleanup dnscache

Type dscacheutil-flushcache and press enter.

Type lookupd-flushcache and press enter

2.Cleanup Lync cache

1)Display Library by runningCMD: chflags nohidden ~/Library/

2)You’ll find the endpoint cache file in a differentlocation, however. To resolve it on the Mac, do a CMD-Q on Lync to make sureit’s completely exited. Using Finder, visit:~/Documents/Microsoft UserData/Microsoft Lync Data/[email protected] . You’ll find the file “EndpointConfiguration.cache” inthere. Delete it and restart Lync. It should now connect.

3.Enable logging.

Log on to Microsoft Lyncfor Mac

1. Click the General tabin preferences to enable logging.

NOTE: After logging hasbeen enabled in Preferences, sign out of or exit from Microsoft Lync for Mac,and then restart Microsoft Lync for Mac.

2. The logs are locatedin users/username/library/logs/Microsoft-Lync-0.log. (The zero increments asthe log file grow.)This will create a log called “Microsoft-Lync.log” and update it in real time

4.Unfortunately Istill couldn’t login. The weird idea, as mentioned in Tom Laciano’s post, touse a wrong user id (I used a “\” in front of my user name) finally made itwork. Of course it didn’t work with this wrong user name, it generated a loginerror message again. But once I entered the right username afterwards itworked.

5.Lookup a “unknown”certificate in your Keychain and delete it. How to manage is well describedhere. Unfortunately, this didn’t fully solve the issue.

6.Under the advancedtab on the Lync login screen I added the server namesipdir.online.lync.com:443. Afterwards the error message changed.

7.update to the latest version.

1)Uninstallthe Lync client: http://support.microsoft.com/kb/26918702)Beforeyou install the Lync for Mac 2011 14.0.5 update, make sure that you have Lyncfor Mac 2011 14.0.0 installed on your computer. Also, make sure that thecomputer is running Mac OS X 10.5, or a later version of the Mac OS X operating system.
To verify that the computer meets the operating system version prerequisite, click About This Mac on the Apple menu.
To verify that Lync for Mac 2011 14.0.0 is installed on your computer, followthese steps:  
On the Go menu, click Applications.
Open Lync for Mac 2011.
On the Lync menu, click About Lync.
In the About Lync dialog box, notice the version number that is displayed. The versionnumber should be 14.0.0

8.Theresolution is cleanup the cache in mac, and restart the lync.