@karthik04, can you please confirm that an associated action exists or existed for the SunOS endpoints and updates in question? Also, do you have any of the yyyyMMdd.log files from any of the targeted SunOS endpoints where we can cat|grep for the action ID?
Assuming that an action installed the SunOS update in question, and no other administrators or other automation systems haven’t uninstalled said update, then I would look at communication failures. However, in most cases the local BESClient yyyyMMdd.log files will contain the needed details.
That said, it may be necessary to enable BESClient debug logging on one or more of the SunOS endpoints and re-run your SunOS updates to collect additional details for a support case.