Event ID 57006 - Cannot restart the Lync Server 2013 Front-End service

When installing CU updates for Lync Server 2013 make sure to update the backend database.  If you fail to do this crucial step you will more than likely receive this error.

http://support.microsoft.com/kb/2809243

Lync Server 2013 Standard Edition:
Install-CsDatabase -ConfiguredDatabases -SqlServerFqdn frontendserver.fqdn -Verbose

Lync Server 2013 Enterprise Edition
Install-CsDatabase -ConfiguredDatabases -SqlServerFqdn sqlserver.fqdn -Verbose