SCOM 2012 management server shows not monitored status

I installed SQL Server Std 2012 and SCOM 2012 R2 in the same VM Windows Server 2012 R2 Std.  Initially the management server shows not monitored.  So I imported the management pack and also disabled firewall.  I checked the event viewer and got this common error --

OpsMgr Management Configuration Service failed to execute bootstrap work item 'ConfigurationDataProviderInitializeWorkItem' due to the following exception

System.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)

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What could possibly cause this?  I've been stuck with this for a couple of days and didn't find a solution.  Any help is appreciated.

Elaine