Clearing old warning alerts
We are using OEM Database Control 11g (comes as part of the database). There is an old alert for User Logon Time (msec) that is dated Oct.29, 2013 (serveral months old). I usually clear these types of stale alerts by disabling and enabling the metric. But when I edit the collection settings for User Logon Time (msec), the collection indicates enabled and does not give a button to disable. Why can I not disable this metric? How do I remove this stale alert?