An error occurred in the SharePoint Portal Alert service. One of the alerts cannot be sent, and results for the alert will not appear. There may be errors in the .xsl file.
Do the following:
Check the .xsl files for any errors that might cause the transformation to fail.
On the SharePoint Portal Server Central Administration for Server_Name page, in the Component Configuration section, click Configure diagnostic settings.
On the Configure Diagnostic Settings for Server_Name page, in the View Diagnostic Logs section, click the entry for SPSNotificationService.log that includes the time when this error occurred, and then click View Log.
In the log file, view the details for this error for more information.