A good source of information in troubleshooting any server issue is the event log. Lync Server 2013 creates a dedicated event log for informational activities, warnings, and errors within the standard Windows Server Event Viewer console. To view this event log, use the following steps:
1. Click Start.
2. Type eventvwr.msc
and press Enter to open the Event Viewer Microsoft Management Console.
3. Expand the Applications and Services Logs folder.
4. Click the Lync Server log.
5. Examine the log like shown in Figure 9.10 for any warning or error events that might provide additional insight into any issues.