For SEP for Macintosh, there is no RU6a (11.0.6005). It's either 11.0.6000 (162) (RU6) or 11.0.6100 (0179) (RU6 MP1). Or do you mean something else?
As I understand it, the fix that is noted for RU6 MP1 (below) had the side-effect of resolving this build number issue as well.
Managed clients fail to display management information after a period of time
Fix ID: 2075100
Symptom: Managed Symantec Endpoint Protection for Macintosh clients stop displaying management information after event rewrites the SymantecRegistry.xml file to zero-byte size.
Solution: Added functionality to remediate the SymantecRegistry.xml when the file is corrupt or missing.
sandra