If you need to debug Lync Server 2013 on Windows Server 2012, you are best of running it on a full server UI (not Server Core or the minimal UI).
I have experienced that without it, the Snooper tool won’t be able to show you a parsed view of the log files, only the raw logs.
This view contains no entries:
The Trace view works:
I’m still trying to figure out why group IM doesn’t work in my Lync 2013 pilot pool, but making Snooper work is a step on the way.