Spotlight uses Powershell to get cluster information from Windows 2012 but the way it works is that Spotlight assumes that a SQL Server 2008 R2 instance would be not be installed on a Windows 2012 host.
Below is work around:
1. Copy the file {DS dir}\Agent\conf\Package\sqlserver_spotlight\2012\QS_ClusterInfo.sql to the directory {DS dir}\Agent\conf\Package\sqlserver_spotlight\2008 where {DS dir} is the Diagnostic Server installation directory.
2. Restart the Spotlight Diagnostic Server service.
