The Object is captured from the "objectName" property, the Severity is captured from "severity" property sent from the Orion. If these values are missing, then the Orion server doesn't send them to Alert Central. Can you check that the "objectName" property is present in the "Original Orion alert" tab in the Alert view? Also can you check that the Severity field is set in the "Alert Sharing" tab for the "alert me if a node goes down" in Advanced Alert Manager application in Orion server? Did you make any changes in definition of this alert? What version of NPM are you using?