Recently I had issue which occured without any particular reason on SQL Server 2012. All of the sudden I start getting error message:

Cannot connect to WMI provider. You do not have permission or the server is
unreachable.
Note that you can only manage SQL Server 2005 servers with SQL
Server Configuration Manager.
Invalid Namespace.

when tried to run SQL Server Configuration Tools.

What resolved situation is command:

mofcomp C:\Program Files\Microsoft SQL Server\100\Shared\sqlmgmproviderxpsp2up.mof