Hi Nick,
The Operations Manager event log and possibly the F5 Monitoring Log (in the Event Viewer) would tell us more about the error. If you zip and send them to managementpack(at)f5(dot)com, we can take a look and hopefully find the root cause of the problem. Usually when this type of error occurs, privileges involved around reading / writing SQL, registry, etc. data are not sufficient and I would probably start looking into the SCOM action profiles involved in data source I/O:
1. "Default Action Account" profile: SCOM Management Console >> Administration >> Run As Configuration >> Profiles >> Default Action Account >> Properties >> Run As Accounts and make sure the action account specified there has enough privileges. The "Local System Action Account" should probably be appropriate. If it's a different action account, you'll have to check the privileges in the Run As Configuration >> Accounts section.
2. "Operational Database Account". Make sure the underlying action account has enough privileges on the OperationsManager SQL database. By default, if no action account is specified for this profile, the SCOM SDK service account is used.
You also mentioned that the SQL Server is off-box from the RMS. I would run the sp_who2 (system stored procedure), using the SQL Server Management Studio, to find who's trying to access the Operations Manager database. Look for the relevant HostName, DBName (OperationsManager) and Login fields in the output. Normally you should be seeing the SCOM SDK service account and possibly the RMS local system account trying to access data. Unless there are other (non-default) mappings for the SCOM action accounts mentioned above (in 1 and 2). Make sure read-write privileges on the SQL data are in place for these accounts in the Operations Manager SQL database.
Julian
(F5 Management Pack)