SDK service cannot be started anymore

If following events get logged into the Operations Manager Event Log:


An authorization store exception was thrown in the System Center Data Access service. Exception message: Unable to perform the operation because of authorization store errors.

OpsMgr Management Configuration Service failed to execute 'AgentAssignment' engine work item due to the following exception

System.ServiceModel.FaultException`1[Microsoft.EnterpriseManagement.Common.UnknownAuthorizationStoreException]: The creator of this fault did not specify a Reason. (Fault Detail is equal to Microsoft.EnterpriseManagement.Common.UnknownAuthorizationStoreException: Unable to perform the operation because of authorization store errors. ---> System.Runtime.InteropServices.COMException: The security ID structure is invalid. (Exception from HRESULT: 0x80070539)
   at Microsoft.Interop.Security.AzRoles.AzAuthorizationStoreClass.Initialize(Int32 lFlags, String bstrPolicyURL, Object varReserved)
   at Microsoft.EnterpriseManagement.Mom.Sdk.Authorization.AzManHelper.Initialize(String pathToStore, String appName, AzManHelperModes helperMode, String storeDesc, String appDesc)
   --- End of inner exception stack trace ---).

you should check the Logins on the Operations Manager DB. It seems that there cannot be multiple users with db_owner role.

Issue is described in more detail here:

Other errors as

Application Error (Event ID 1000)
.NET Runtime (Event ID 1026)

Faulting application name: Microsoft.Mom.Sdk.ServiceHost.exe, version: 7.5.3070.0, time stamp: 0x520d7e93
Faulting module name: KERNELBASE.dll, version: 6.3.9600.17055, time stamp: 0x532954fb
Exception code: 0xe0434352

can be also be logged in the application event log.