If your management servers have their System Center Data Access Service (SDK/DAS service) running as a domain service account, you may get the following error each time the management server(s) or SDK/DAS service is restarted, even though all SPNs are correctly registered:

Alert Description
Source: Data Access Service - SCOM01.contoso.com
Full Path Name: SCOM01.contoso.comData Access Service - SCOM01.contoso.com
Alert Rule: Data Access Service SPN Registration
Created: 26/08/2015 15:43:06

The System Center Data Access service failed to register an SPN. A domain admin needs to add MSOMSdkSvc/SCOM01 and MSOMSdkSvc/SCOM01.contoso.com to the servicePrincipalName of CN=SCOM01,OU=Users,DC=co  ...