One or more alert notification subscriptions encountered an error while attempting to run. Some or all notifications may not be correctly delivered.
The Alert criteria selected for the Subscription may be returning an error when used to filter Alerts in the Operations database. The Operations database has errors and hence maybe causing the wrong information to be sent to Reporting server. It is possible that the state of Notification subsystem is corrupted and it cannot read or write the state of this notification. Notification subsystem was unable to generate a notification message due to errors in the Notification runtime.
Notification subsystem is unable to generate notification messages due to availability problems. This may be due to one of many reasons.
Check the subscriptions in the Management group. If there are any subscriptions that have complex queries associated with it they can slow down the generation of all notifications. See if you can simplify the criteria for the alert.
Check if the subscription information has been set correctly.
Validate any other error messages in the Operations Manager Event logs for problems.
Inspect the messages in the Operations Manager event log. Other indications of problems in the system may direct you to further diagnostic steps. There may be other failures in the Operations Manager runtime.